The Quad Core will handle 2009 fine. I'm using one now. Unfortnately I don't have TRS2009 yet to tell if it will make a difference.
If you have the opportunity to get one, go for it. I recommend the 64-bit verions of Vista to support the processor though. With the 64-bit OS, I've noticed other system functions have less overhead on the computer as well and are faster with disk I/O functions such as defragging being quite fast.
John