Well I put Windows 7 on my Mac Pro (running 10.6.1) on a separate internal hard drive. When I fired up /Applications/Utilities/Boot Camp I directed to look for the separate hard drive (in internal bay 3). Then it had me restart with the windows 7 DVD. Before the Windows 7 install I formatted the disk NTFS (for large work files) and powered on with the install. After using the Snow Leopard (retail version) disk to install the Boot Camp drivers. Windows 7 found everything in my Computer (after doing all the Windows Update after the Boot camp install ) and Windows 7 got all the update drivers.
The only thing that is frustrating me is my Broadcom wireless card and Windows is not able to find the hidden 5 Ghz range on my new Time Capsule, only the g range. I am still trouble shooting this though and am hopeful because Windows 7 updated the wireless card drivers when i last shut down. It is still a work in progress.
The only other thing was the two Firewire 800 hard disks. Don't let Windows 7 try to format them automatically. I forgot tot turn that off and lost all my external data on them (they were were recoverable but still lost the data on them after reformatting).
Everything else in Windows 7 was recognized. The thing one has to remember is to install the Boot Camp drive and after that run Windows 7 update. It will find updated drivers for the drivers boot Camp had, and it works after that with the latest windows drivers. The only other thing there is no longer a Startup Control Panel installed by boot Camp. The Control panel is combined in to a Boot Camp Control panel to select a startup disk.
So take the plunge it is almost like Windows Vista SPA2 install. The boot Camp drivers that were installed on Vista will work in Windows 7. The change apple is hoping for is the license from Microsoft for OS X to read/write. Read/Write to NTSF is in 10.6.1 but it is unstable (cause Kernel panics), that why it isn't turn on.
Mac Pro Dual 2.8 Quad (2nd gen), 14G Ram, Two DVD-RW Drives, OS X 10.8.3
2006 Mac Book Pro 2.16 (first Gen) OS X 10.7.4
2TB Time Capsule, 2 TB
32G iPhone 4S Black, iPad (3rd Gen) 32G Black