AnandTech took a look at the motherboard compatibility of the new Intel Wolfdale and Yorkfield processors:
We have spoken at length with the various motherboard suppliers and have a fairly good indication of what motherboard/chipset combinations will work with Wolfdale and Yorkfield (the desktop Penryn codenames for dual-core and quad-core, respectively). The recently released Intel P35, P31, G31, G33, G35, and X38 chipsets have native support for the 45nm processors. However, even though these chipsets fully support Wolfdale and Yorkfield, the motherboards based on these chipsets could require something as simple as a BIOS update, or - in the worst cases - a new board revision.
In the vast majority of cases with these particular Intel chipsets, the motherboard will POST and operate even if the BIOS does not fully recognize the processor. However, in early testing of the processors we have noticed that most of the motherboards will require a BIOS update in order to properly optimize the performance of the system. We expect to see a flood of BIOS updates over the coming weeks that not only recognize each 45nm processor, but also provides specific performance optimizations for each board.