In using F15 updates-testing, it brought the 220.127.116.11-27.fc15.x86_64 kernel, xf86-video-intel 2.15.0 (instead of 2.14.0), Mesa 7.11-devel still (obviously), and was still with X.Org Server 1.10.1. These results are being delivered from the aforementioned Hewlett-Packard EliteBook 8460p.
Intel Sandy Bridge graphics should work fine under Fedora 15, just know that there are more performance optimizations to be found if you're after the best OpenGL performance from the low-power Intel integrated graphics. There might also be a performance issue related to GNOME Shell / Mutter, which is still being explored. What's important though is that when using Intel SNB "out of the box" on Fedora 15, everything is working and we weren't hitting any lock-ups or other problems like we have on other distributions.