Theorycrafting is still being done. I haven't had a lot of time to look at it, but it appears that it's a nerf below 300int, a buff above 300 int. I'm still sketchy on some of the details. The initial equation people are using is:
Regen_mp5 = 5*0.00932715221261 * sqrt(Int) * Spirit
And more discussion (I'd recommend you at least read the entire thread before posting, if you post at all):
http://elitistjerks.com/f31/t21280-intellect_-_spirit_conversion_ptr_theorycrafting_hq/
Edited, Feb 12th 2008 11:56am by lsfreak