As far as Hamilton goes, the only perspective I have of his ability to contribute right away is from an article on ESPN.com a week or two back highlighting the Big 12's Recruiting thus far. Here's a quote from Iowa State's portion:
"Hamilton, with current Iowa State center Jiri Hubalek scheduled to depart in 2008, also has a chance to see significant playing time when he arrives on campus. Hamilton runs the floor very well for a big and blocks shots at a very high rate. He plays with a high level on energy and competes for rebounds, though he needs to improve his post game and add strength for the rigors of the Big 12."
ESPN.com 2008 Big 12 Recruiting Breakdown
Hard to say whether or not they actually know much about the kid, though...I agree with RickyBaby in that he looks like a stick...