Since the publication of the transient ID book in 1999, much has changed in the ever-evolving population of mammal-eating orcas. Here are the updates I've been able to track down. Much of it is not specific and I'm sure there's lots I've missed. I will be constantly trying to update this.
The notes on who travel together are to keep you updated on the constant changes in transient travel patterns. If there are no notes, then I have no idea. 'Unknown status' simply means no known changes, and basically no information.

T2 Group
*T2, T2C, T2C1, T2C2 travel together
*T2B and T2B1 travel together
-T1, presumed dead, was seen in 2003
-T2A is presumed dead as of 2002
-T2B travels separate from her family & gave birth to T2B1 in September 2006
-T2C still travels with her mother; she gave birth to T2C1 in September 2002 and T2C2 in 2005

T7 Group
*T7, T7A, T7b travel together
-T7B's offspring no longer travel with the group; they may have died or simply dispersed

T10 Group
*T10, T10B, T10C travel together
-T10A is presumed dead 2002
-T10 gave birth to T10C in 1999

T11 Group
*T11, T11A travel together

T12 Group
*T12, T12A travel together
-T12B is presumed dead 2002
-T12C is presumed dead 2004
-T12 was rumoured to have a calf 2000, but it's unknown what happened to it or if it even existed

T13 Group
*T14 travels alone or with various other transients
-T13 is presumed dead 2000
-T14 is sighted frequently in the company of various other transients

T17+T18 Group
*T18, T19, T19B, T19C travel together (T17's status unknown)
-T17 may have been seen in 2003 with the T18s
-T19 gave birth to T19C in 2001

T21 Group
*T20, T21 travel together
-T22 is presumed dead 2004
-T21 went missing for a few sightings, but returned in 2002
-T20's dorsal leans to the left

T23 Group
*T23, T23C, T24 travel together (T24 & T23D's status unknown)

T26 Group
-Unknown status

T28 Group
*T28, T28A, T28B, T28C travel together
-T28 gave birth to T28C between late 1999 and early 2006
-T28A is male and beginning to sprout

T29
*T29 either travels alone or with various companions

T30 Group
*T30, T30A, T30B, T30C travel together
-T30 gave birth to T30C between 2001 and 2004; the calf was around 2-3 years old in 2006, when a VHF radio tag/suction cup time-depth recorder was attached to it. The baby was recorded diving 797 ft, the deepest dive recorded in a transient
-T30A is a male and has sprouted

T32 Group
*T31 often travels alone
-T32 is presumed dead

T34 & Co.
*T34 is often sighted alone; unknown status for others
-T36A may be female; she may have had a calf around 2005

T40
*T40 either travels alone or with various companions
-Seen with large group of transients in 2006

T41 Group
*T41, T41A, T44 travel together
-T41A is female and has a new nick slightly down from the top of her fin
-T44's fin is hooking forward
-The three are quite commonly spotted since 2002

T46 Group
*T46, T46C, T46D, T46E, T122 travel together
*T46B & T46B1 travel together (occasionally both groups travel together)
-T46A is confirmed as the same animal as T122, and is now known by that ID
-T46 gave birth to T46D between 1999 and 2002
-T46 gave birth to T46E in 2003
-T46B gave birth to T46B1 in 2003
-A new calf was born to the group around 2006, but it is unknown who's calf it is; most likely it is NOT T46B's

T47
*T47 may travel separately from the T46s

T48
-Unknown Status

T49 Group
*T49, T49A, T49A1, T49B, T49C, T51, T53 travel together
-T49A is female
-T49A gave birth to T49A1 between 2000 and 2005
-T49 gave birth to T49C between late 1999 and 2004
-The status of T50 and her offspring is unknown; they may have dispersed of the group or died

T55 Group
-Unknown status

T59 Group
*T59, T59A travel together
*T60, T60C, T60D travel together
-T59A is possibly female
-T60 gave birth to T60C between 2000 and 2005
-T60 gave birth to T60D between 2001 and 2005
-T60B's status is unknown; it may have died

T61
*Often spotted alone or with various companions

T64 Group
*T63, T65, T65B travel together
-T65A was seen separately in 2005 and has probably dispersed of the family
-The status of T64 & T64A is unknown; they may have left the group

T66
-Unknown Status

T67
-Unknown Status

T68 Group
*T68C appears to travel alone
-The rest of the group is unknown status (T68C may have left the group)

T69 Group
-Unknown Status

T70
-Unknown Status

T71 Group
*T71, T71A, T71B travel together
-T71 gave birth to T71B between late 1999 and 2005

T72
-Unknown Status

T73 Group
*T73, T73B, T73C, T74 travel together
-T73 gave birth to T73C between late 1999 and 2003
-T73A's status is unknown; it was travelling with the group in 2003 and may have died or left since
-T74's fin has been injured and is deteriorating

T75 Group
*T75, T77, and T78 all travel separately and possibly alone; their offspring's status is unknown
-T77 gave birth to T77B between 1999 and 2003; she and her two offspring were travelling together in 2003

T79
-Unknown Status

T81 Group
-Unknown Status

T82
-Unknown Status

T83 & T84
-Unknown Status

T85 Group
*T85, T85A, T85B, T85C travel together
-T85 gave birth to T85C between 2000 and 2006
-T85A is male and is sprouting
-The status of T86 and T86A is unknown

T88 Group
*T87 and T88 travel together
*T90 travels separately but is occasionally seen back with the other two
-T89 is most likely dead

T91 Group
-Unknown Status

T93 & Co.
*T93 and T94 travel together
*T97 often travels alone
*T96 has branched away from the group
-T95 may be missing, but she also may just be separated
-T96 seems to travel alone now (he was still alive as of 2006)
-T97 is male

T99
-Unknown Status

T100 Group
*T100, T100B, T100C and T100D travel together
*T101, T101A, T101C, T102 travel together (Note: both groups travel together frequently, although they also split apart occasionally)
-T100 gave birth to T100C between late 1999 and 2004
-T100 gave birth to T100D around February 6, 2006
-T100B is probably female
-T101 gave birth to T101C
-T101B is either dead or has left the group
-T102 is male has sprouted 2006
-T101A had a suction cup time-depth recorder attached to it September 15, 2006; it sayed on 10 hours
-T100B also had a suction cup time-depth recorder attached on September 10, 2006; this one stayed on for 13 hours

T103 and T104
*T103, T104 travel together
-T104 is female

T105
*Travels alone or with various company

T108
*Travels alone, or often with the T109 group

T109 Group
*T109, T109A, T109B, juvenile, calf travel together
-A calf and juvenile were born into the group, but their mothers haven't been established; the juvenile was most likely born to T109 (and may be T109C)
-T109A is probably female

T111 Group
-Unknown Status

T116 Group
-Unknown Status

T117 Group
-Unknown Status

T118 & T121
-Unknown Status

T22 & T123
*T123 and T123A travel together
-T123 gave birth to T123A between 1999 and 2004
-T122 travels with the T46 group and is actually T46A

T124 Group
*T124, T124D, T124E travel together
*T124B and T124B1 travel together
*T124C has split off on her own
*T124A, T124A1, T124A2, T124A3 travel together
-T124C is female
-T124A gave birth to T124A2 between 1999 and 2005
-T124A gave birth to T124A3 in 2006
-T124 gave birth to T124E in 1999
-T124B is female and gave birth to T124B1 between 2000 and 2004
-A time-depth recorder was attached to either T124C or T124D, September 2006
-T124A and T124A1 were two of the 2005 Hood Canal transients
-The group has split into 4 groups

T125 Group
-Unknown Status

T129 & Co.
-Unknown Status

T137
-T137 gave birth to T137A prior to 2005

T139 Group
-T141 is female and gave birth to T141A between 2000 and 2004

T143 Group
*T142 apparently travels by himself sometimes, but is also seen often with T143 and T144 as recently as 2005
-T142's fin has a right bend

T145
-Unknown Status

T146
-Unknown Status

T147 & Co.
-Unknown Status

T153 & Co.
-T153 & T154 were seen travelling together in 2003

T159 & Co.
-Unknown Status

T162 & T163
-T162 may have been seen in 2003

T164
-Unknown Status

T166 Group
-Unknown Status

T168 Group
*T169 apparently travels separately; the others' status is unknown

T170 & Co.
-Unknown Status

T185, T186 & T187
-Apparently identified for the first time after 1999
-T185 is female