There are "Ivy Bridge" CPU's and "Ivy Bridge" motherboards. Not all Sandy Bridge motherboards support the new 22nm Ivy Bridge CPU's which is what I believe you are asking
While there are some Sandy Bridge motherboards that support PCIe v3 (faster PCIe bus) there are several features that only Ivy Bridge has.http://en.wikipedia.org/wiki/Ivy_Bridge_(microarchitecture)
As mentioned above, I believe what you want is a Z77 motherboard. You can buy an Asrock Z77 motherboard for as little as $100. I really don't see the point in buying a Sandy Bridge motherboard now that Ivy Bridge boards cost basically the same.
- PCIe v3.0
- Virtu MVP
- supports the new 22nm Intel CPU's (and current 32nm 1155 for backwards compatibility but I don't recommend that now)
(I'm recommending the new i7-3570K Intel CPU for people building new computers)