A hot new feature in 3.5 SP1 is GPU based effect. Greg Schechter has has a series of posts on this topic. Its well worth the read. So head over :)
Greg Schechter's posts are very handy, for there isn't currently many documentation about those new features. I've wrote a simple tutorial on my blog for french developpers. I'm also going to release a post on an interesting bump-mapping effect using 3.5 SP1 (bypassing its limits, for the beta theorically doesn't allow multi input effects).
Superp new stuff!! ... will the samples be available?...will there be more documentation?