Found a few good reviews on the newest canon dslr, including this one;
http://www.dpreview.com/news/0809/08091705canon_5dmarkII.asp
Would be expecting the pro's amongst the shooters on here may...
Personally I will be sticking with my 40D for a while longer, but I do like the added features especially the HD video capture, the ability to take full resolution shot midst video and the additional cross focus points are nice.
some pretty impressive sample shots also;
wow!! @ ISO 6400:
http://www.flickr.com/photos/37139243@N00/...in/photostream/