Apparently, “by the end of the month” means something a little sooner — i.e., right now: WorldWide Telescope is now available for download. See coverage from Astronomy, Sky and Telescope and Virtual Earth, an Evangelist’s Blog.

It’s a beta (probably permanently so, according to S&T), and the installation process looks complicated. The system requirements also look ferocious. No computer more than two years old will run this machine: it requires a Core 2 Duo processor. (Google Earth is not as demanding.) I have nothing that can run this thing.

Stefan has taken it for a spin on underpowered hardware: “[I]t left a truly stunning impression. This is an amazing tool. If you have a well-specced Windows machine (not Parallels or VMWare on the Mac like me) then drop everything and lose yourself in this for the next few hours.”

Previously: WorldWide Telescope This Month?

Update, 5:40 PM: Reactions from Digital Earth Blog and Uncle Rod’s Astro Blog.