Its official now:
The Announcement: http://www.dpreview.com/previews/canoneos50d/
The Hands-On Review: http://www.dpreview.com/previews/canoneos50d/
Looks like some new sensor technology's gonna squeeze a bit more megapixels in there, probably for marketing. Apparently, that's not going to increase too much noise according to Canon, (I haven't had time to read the review yet.) so we'll see.
Some new features include:
DIGIC 4 processor
15 MP
Peripheral Illumination Correction (fix vignetting in-cam)
6.3 FPS >60 JPEG Large/Fine
new DIGIC 4 interface
Nikon also just announced the D90 as well for all you Nikon lovers,
Heres the review for that: http://www.dpreview.com/previews/nikond90/
Sorry I can't sum that up I haven't read it yet but you guys can do that for me