When I upgraded all my drivers converted right over. The only one I had to remove and reload was my HP 5100 series printer and it came with the vista driver cd. I also had to update the graphics driver for my intel chipset graphics. Which was online. Other than that I have no issues. My wireless network on the other computer took right off also.
I now have mine wired direct to the router and my wife'* core 2 system on wireless (vista) and the kids P4 system (XP) on wireless. Network working fine.
I don't mind the negative input. I have heard a lot already, but i figured I would try it out. I have had the oppurtunity for awhile and just now decided to do it. There are a lot of scary stories out there, but there was about XP when it came out too. I am actually enjoying it though.