I just installed the Windows 7 release candidate as a dual boot on my laptop.  If all goes well I will scrap Vista.  So far so good.  It didn't autodetect my nVidia graphics card driver but I got that from the HP site.  Otherwise it's been a very easy install.  Also, the RC doesn't come with tons of pre-installed crap so it's a lean system and I'm only installing stuff that I will actually use.