I handled it briefly at the Canon photo workshop up in Maine last weekend (I had brought my 50D so I didn't borrow it) and I really liked the size of the viewfinder (noticeably larger than 50D) along with its 100% field of view. I didn't see this personally, but high ISO performance is also supposed to be much better than 50D. I could care less about its video function, but coming from 50D, the viewfinder was really nice.
What would you be trading for 7D?