I never believed the Bester was telling the truth about Talia being dissected. Unfortunately I also don't think there is any way to restore "Talia 1.0", unless Kosh was thoughtful enough to leave his VCR recording of her personality behind. (I've always thought that this was created as a way of getting Talia back if Andrea hadn't quit the show.)
In the final volume of the Telepath Trilogy Garibaldi ponders Talia's fate. It is the 2270s and he's the enormously rich head of Edgars-Garibaldi, has influence at the IA and in EarthGov, and has seen his one-time nemesis, Psi Corps, destroyed. Yet for all his wealth and power he's never been able to find out what happened to Talia after she left B5 or uncover even a trace of her.
That's pretty ambiguous, but that's where JMS left it.
I think he was a little ticked off at Andrea and what he saw as her non-team-player attitude when she quit, and he was happy both to see her go and to arrange her exit in a way that made her ever returning very unlikely.
But things change over time, and it may be that Andrea's participation in the DVDs and her career since might make her (and therefore Talia) an asset to future B5
projects. (Thanks to the several years she put in on NYPD Blue
, which is in heavy rotation on both TNT and Court TV, her brief but publicity-filled stint at Headline News and her recent appearances on 24
, Andrea may have a higher industry and audience profile than anyone in the cast besides Bruce Boxleitner.)
It might be interesting, for instance, to have Talia show up in a Teep War story.
Who knows? Thermo Teep Lyta may have been given either Kosh's data crystal or the information it contained and be able to restore Talia to her original personality. Or she might be able to do it all on her own thanks to her increased powers. (Maybe Talia 1.0 was merely supressed, not totally destroyed.) There are all kinds of possibilities there.