the 5D mark II is a damn hot camera... absolutely love mine, though i will admit, i find myself using the 7D more and more lately...
while the 5D has the advantage of the full frame sensor, the 7D is a much faster camera to work with... it had advantages across the board, from a 19 point AF system, faster frame rate, faster lenses, faster focusing, better movie control... all in all, i actually prefer using the 7D for every day photos and work...
the 5D's full frame sensor is the only thing that really makes it stand out against the 7D... without that, it's simply a reasonable camera but pretty slow with most things... For example, even taking the F-stop down as low as you can, you're still not going to be able to accurately capture 'freeze frame' moments for action or movement, the full frame sensor just doesn't work like that... it's absolutely fantastic for portrait or landscape shots, but any hint of movement in the frame and your entire focus system and shot goes out the window altogether...
All in all, i'd highly recommend the 5D for portrait and still life shots, the full frame sensor is above and beyond the rest when it comes to that style of photography...
But if you're looking to capture sports, movement or anything where focus and lens speed are important to you, then go with the 7D
M