I agree that he's too talented but I have a few thoughts.
1) Perfect fit. They lost Yao and Dikembe last season, and they need height and talent in the middle in front of their stalky young forwards.
2) Even if Yao comes back, he will still fit in a little better than some of you are giving him credit for. Yao plays alongside hustle guys that hover around the paint and try to rebound. He can do this because they have shooters to kick to our of the double team, and also because Yao can hit outside shots with consistency (a few against the Lakers with his heels on the 3 point line). That will give Gortat the ability to run that same offense and opperate using hustle in the paint. He also can D up most 4's to play some minutes alongside Yao. Great sigining opportunity.
Thoughts?