Things that won't run on my x64 machine...

I have had very few programs refuse to install. Most just run as 32 bit without issue.

These programs will not install...

1. Daemon Tools - new release (v4) that will support x64 expected soon.
2. Virtual Server - R2 version update will support x64. Currently in beta.
3. MSN Desktop Search - no update expected that I could find
4. Google Desktop Search - no update expected that I could find.
5. Printer driver for Dell Inkjet 720 - presumably all Dell inkjets?
6. cvsnt - at least it won't run. Not sure of the actual issue. Does great in win32.

This one requires a simple workaround...

1. x64 Flash plug-in (and all other plug-ins as far as I can tell) - no mention of an update coming that I have found. 32-bit explorer works just fine though.