Install it and give it try with your hardware, some scanners and printers are older and may not have Vista drivers posted on the product pages for download. Vista drivers generally work on Windows 7 at this point. It's old hardware that may not cooperate due to poor driver or no driver support with Vista, or in your case Wincows 7. Not M$'s fault your printer company doesn't provide a decent Vista driver or in some case no driver at all
I have had the original Windows BETA 7 running since the day of release. Now Windows 7 RC is up and running nearly an entire day now since it's release last night. Currently have Windows7 RC running on a socket 939 NF4 with a a single core AMD 4000 San Diego at 2.5 or so. I'm thinking of buying an SSD drive and dual booting it on a decent fast machine and learning how to use to my best advantage for when the initial retail release is on the shelves. The RC version of Windows is nice and fast so far. And on an old, slow by today's standars machine. It's always easy to simply load up Vista or XP if you decide Windows 7 RC is not what you wanted currently.