Upload & Sell: On
I've never owned the 50D, but I would re-purchase the T2i before I bought a 50D. That means that I'd jump at the new T4i even faster. Better IQ, video, 18MP, tilty touch screen -- what's not to like? 50D never had outstanding sensor -- I far prefer my 60D, despite the complaints I've heard from 50D fans that were disappointed when the 60D came out.
If, by chance, you find the T-series AF is front or back focusing, simply send it in with the lens or lenses to Canon and they will get them all adjusted for you under warranty. Maybe up to two or three lenses -- I've never seen a written policy. That's what I did on my T2i that front-focused -- came back great and worked with most of my lenses perfectly after that, including EF-S 60/2.8 Macro.
With an aftermarket grip.