I have seen people say they've used it successfully because I've been wondering the same thing. Mainly, I was thinking I might unroot before the 3.1 push.
I can't find the discussion at the moment, but I saw that on a thread here or another forum. I've yet to try it though.
It does work just fine.
I have rooted and unrooted several times with no problems.
My tab seems to lag a bit more after rooting than with root, even while running setcpu. Not sure why.