A little late, but I'm behind in my blog reading (and posting). From the Writer DevZone:
We have heard from many of you about the pain and frustration in the last beta release when support for installing on x64 systems was not supported. We're happy to share that this has also been fixed and now installation on Windows Vista x64 is fully supported.
Very nice! Now I can actually install and run it (posting from it now). I really like the new installer and also installed the Live Photo Gallery app on my desktop. The app allows you to upload photos to spaces and also has support for uploading to Flickr. I really would like to extend this for my own custom photo service that I wrote for my family to share photos, anyone know if this is possible?