"As we reported earlier this month, Apple missed its self-imposed deadline of the end of 2009 to release the software update required to dual-boot Mac OS X 10.6 (aka Snow Leopard) and Windows 7."
I've been using Windows 7 and 10.6 on my Mac Pro for months now without problems. Boot Camp 3.1 is definitely not required to dual boot. I believe it's just the first officially supported version. I just checked, and I have 3.0.1.