IMHO, the 5D-II focuses somewhat faster than the 5D with F2.8 lenses using the centre point. It also seems to work better in noticeably lower contrast. The peripheral points have not improved sufficiently for me to use them in my work.
On the whole, the 5D-II in a reasonable incremental improvement over the 5D. However, I do wish they would have put in a fancy, fast and reliable focus system rather than a fancy video system. But then, Canon has never listened to me before so why should the do so now :-)