As far as I know, the Thoroughbred will only offer a shrink to 0.13 Micron and offer higher clockspeeds with a lower voltage and less heat... Doesn't sound like the new processor will offer much more than raw speed and better overclocking margins ... (which isn't a bad thing at all!)
I think the first Athlon XP based on 0.13 micron manufacturing will be released as the Athlon XP 2300+ and should be out sometime in Q2 2002 (So sometime in April - June)