Actually, the version 4.0.4 does support Windows 7. I virtualized vSphere client and it ran on Windows 7 32-bit. Also, I virtualized some others app and they run as well. The problem is you will have to re-capture all the apps that you want to run on Windows 7. I have not test it with the 64-bit which you need to turn on "WoW64" option in the pacakge.ini. The trick is you need to install .NET 3.5 SP1 first.
As for version 4.5 release, talked with VMware ThinApp and they said it "schedule" to release in first quater of 2010.
Cheers,