I'm using Vista 64-bit and currently a trial of Elements 7. Now it isn't a native 64-bit app (runs as a 32-bit app on Windows 64-bit), maybe that's what you meant. And because of that, it won't take advantage of all your RAM and it is a little slower than some of the other Photoshop apps.
I also have a full version of Elements 6 which the editor works fine but the organizer is flawed when using RAW (a known bug they didn't fix until 7).
I'm also using Bibble Pro (4.10 full version and 5 preview edition) as well as Lightroom 2.3 (using a trial at the moment and I will be receiving my full version any day now).
Between Bibble, Lightroom, Noise Ninja and Elements 7 I am able to do 99% of what I need to accomplish.
The main gripe I do have with Elements is that I can't work in 16-bit TIFFs, it down converts them to 8-bit. And it also doesn't use the ProPhoto RGB colorspace (only SRGB and Adobe RGB).
Paul