Yes, from what I've heard around the Internetz. I have not personally confirmed it, but have read several accounts.
Also, I've heard that there are additional stock CPU descriptions in software that aren't released yet but will be when the new Mac Pro hits the streets, further increasing the support for newer CPUs.
I've got a Xeon E5 2620. Most of the discussion out in the ether seems related to the newer Ivy Bridge - E processors.
Exciting times.
D
ETF: wrong proc number