Hi,
since I switched to an F2A-85M I have a spare gigabyte desktop board with the Intel X4500 onboard graphics (quite rare) which has afaik no coreboot so far. In general, it seems like only one other socket 775 board is supported. I was wondering if this could be an interesting target or if any major showstoppers are to be expected. Here's are the specs:
http://www.gigabyte.com/products/product-page.aspx?pid=2877#sp
Although the board just supports DDR2 memory (4 slots), with the Socket 771 pinmod it should be able to run quite decent and cheap Xeon quadcores.
Cheers, Daniel