I would only recommend a 975x to someone that wants to crossfire. Otherwise the p965 is a better choice for your money. I am really anxious to see what the 650i ultra boards are gonna be like when they come out from a price/performance standpoint. It would be nice to finally have a fairly inexpensive motherboard for Intel with nvidia chipset.
The 965P does, in fact, support x-fire. (Gigabyte DQ6. Scroll to bottom
The 965P overclocks better than the 975X, and it has the better southbridge. It also has a better memory controller.