About a month ago my new ThinkPad Z61p arrived. It came pre-installed with Windows XP, but I always do a clean install to remove all the junk that comes with a new system (although Lenovo isn't nearly as bad as some OEMs). I decided to be adventurous and install Vista Ultimate x64.
Virtual PC 2007
I copied the harddisk of my old laptop to a VHD file, so that I would be able to use Virtual PC 2007 to run my old configuration. Well that was a big mistake. Virtual PC 2007 is a useless piece of crap. First of all, it had problems with the VHD file because it was bigger than 64GB (which surfaced as "Sector not found" errors in the virtual machine) and after I resolved that by shrinking the disk to 60GB the performance was horrible (it appears they *still* haven't solved the laptop/chipset/keyboard responsiveness issue). After getting fed up with that I switched to VMWare 6.0 beta and I have been very happy with that (I've been a VMWare user since 1.0, but wanted to give Virtual PC 2007 a chance since it's free [as in beer] now.)
The fact that the harddisk was *always* busy drove me crazy (and made things often very slow), so I've disabled the Windows Search indexing service, after doing that and using a 2GB Kingston USB memory key as a ReadyBoost cache performance is acceptable. It's hard to compare with my previous XP system, because I also switched to Office 2007 and Outlook 2007 is a real pig.
The integrated WiFi doesn't work. It looks like the driver works fine (I can see all WiFi networks in the area just fine), but when Vista tries to establish a secure connection, it fails (well, it actually succeeds and then breaks the connection again after a few seconds). All of the built in diagnostics crap is totally useless (as expected). The built-in flash reader also doesn't work (the Lenovo support site doesn't have a driver, but with some Googling I was able to find one, but it was very unstable).
I've switched my main IKVM development environment to Visual Studio 2005 (but will still support .NET 1.1) and when I do my test builds I now build in 64 bit mode. This works surprisingly well and the performance is excellent. I was a bit skeptical about the x64 CLR JIT because of my previous experiences on Windows XP x64 (the performance there basically sucked), but the Vista CLR build (which is a newer build) appears to have fixed that.
As a result of running on .NET 2.0 most of the time now, I've fixed several "ReflectionOny" bugs (when IKVM is built on .NET 2.0 it uses the ReflectionOnly assembly loading context for ikvmc and ikvmstub).