He does a lot of landscape, low light (high exposure), some sports photography.
Landscape and low light will be excellent with the 5DII. Sports will be a challenge with the 5DII's rather poor AF system (AI Servo tracking, in particular) and the relatively slow frame rate. Still, it's a great camera.
The 5D2 AI Servo isn't THAT terrible. Terrible compared to 1 series for some circumstances but otherwise it does AI Servo better than any rebel, any xxD camera, and, IMO, overall, even better than the 7D which can get rather erratic at times for football and soccer. The 5D2 AI Servo can get a bit slow and wacky when your subject is close in though. For a somewhat more distant subjects it sometimes does as well as a 1D2. Not saying it is amazing or anything, but in the Canon world only the 1 series and the 5D3 do AI Servo any better.
It's trigger response time is a bit on the sluggish side compared to some xxD,7D,5D3, 1 series though and it's fps is very slow compared to xxD,7D,5D3, 1 series, it feels like a sloth crawling through molasses after handing the others right before it.
If you need to use AI Servo with something other than center point then it's pretty awful and 7D, 5D3 and 1 series are all vastly better (even some xxD are probably better then (if not very good at all themsevles)).