No, because there are not enough reasons for it yet. The 32 bit version works on 64 bit Windows just fine and many people don't give a damn and would be annoyed if they downloaded the 64-bit version (just because 64 > 32) and then it would not work on their 32-bit Windows. Plus there is a problem with Photoshop plug-ins. Most of them are 32-bit and 32-bit and 64-bit code cannot be mixed in a single process. I would have to work around that to make the 64-bit version able to use Ps plug-ins. It will eventually happen, but as I said above, there are no good reasons to spend time on that right now.
The thumbnails should work, though they are a bit outdated. A new version will come together with the icon editor.