The New York Times gave a small hint when it said that the new Windows Live Software Suite will be the first full release and that the Windows Live installer includes the Windows Live Writer blogging application.
Now we have an indirect confirmation from Joe Cheng who is the main Microsoft developer at the Windows Live Writer team.
Joe probably configured the new Windows Live Writer 1.0 release to work with his blog and that led to a style-detection Temporary Post. Though the post is deleted from the main blog, it stills exists in the cache of my newsreader. (see screenshot)
A temp post is normally created by WLW when you update your blog style. In Joe's case, the blog theme is same as before so he probably did a fresh installation of WLW 1.0. Can't wait to see what goes in the new release.
Related: WLW For Power Users, WLW Tips, Windows Live Writer Plugins