Version 2.30 Beta Build 939 of Windows Updates Downloader was released this morning!
Available for download at http://wud.jcarle.com/
It's not WUD3, but it includes a lot of Vista compatibility fixes and has been recompiled for native 64-bit support. I'd love to get some feedback on the changes and improvements. I believe I only have the file association issue to fix. Everything seems fine but you guys are the ones who will let me know with the wide variety of operating systems and setups that you all have.
Thanks for the support and cheers!