Good old David Rasmussen who is Group Program Manager of OneNote has built (in his "spare" time) a way to send printouts to OneNote 2007 directly on 64-bit Vista and Win7. It's a little clunkier than the built-in 32-bit only solution that comes with OneNote 2007, but if you use a 64-bit OS like I do you've wanted this for a long time.
David's project lives on codeplex, which is an open source location for projects that Microsoft employees work on. If you want to improve David's stuff, go right ahead. It's pretty impressive that a guy as busy as David had any time to do this at all, but the OneNote team has always felt the need to respond to customers and this has been a top request for awhile as 64-bit machines have really taken off since OneNote 2007 was released.