The TG01 had it all on paper - an amazing screen, the first use of the super-fast Snapdragon processor, and a thin build not seen since before Nicole Richie started putting on the pounds. The TG02 will hopefully perform better.
It's not that the TG01 had anything particularly wrong with it, it just didn't live up to its specs. Lag weighed it down, as did Windows 6.5 - which could be the downfall of the TG02, as it's not been updated with the later 6.5.3 by the sounds of it. We presume it'll be available as an OTA update, and perhaps even Windows Phone 7 at a later date, too.
Anyway, the TG02, which we first caught wind of in late January, has a 4.1-inch capacitive display, 1GHz Snapdragon processor and newly designed 3D interface. It's 9.9mm thick, which is only 0.1mm slimmer than the TG01, but is still slinky on the greater scheme of things. One thing I didn't like about the TG01 was the cheap build, so I hope Toshiba's at least used some more premium materials for the TG01.
Update: Full specs below.