A good article over @ Anandtech.com about Sandy Bridge:

Some items FTA related to my 'to build or not to build' questions
- On chip GPU. ?How will this affect gaming performance?
- Obviously, Sandy Bridge means entire new chipset.
- So far, it appears USB 3.0 will not be supported natively.
- SATA6 may still be limited in # of onboard connections (2)? Hmm.
- PCIe 2.0 (or 3.0???) lanes will run at 5.0 GT/s, instead of 2.5 GT/s currently. ?How will this affect gaming performance?
- We are looking at second half of 2011, so what prices and performance will look like exactly is anyone's guess. It's wait and find out or bite the bullet now and upgrade knowing it is obsolete in 6 months... Gah!

I've started reading the post E-Male created back in 2/10 on his build. Some helpful advice to be had there.