The Gartner blog
Michael Silver of Gartner posted an interesting blog entry today about Windows Vista and Office 2007:
http://vista.blog.gartner.com/blog/index.php?itemid=1591
It addresses a topic that was active on the MSSMS list today: when will Vista ship. While he doesn't get into exact dates either, it does at least acknowledge that it will be sooner than Gartner originally predicted 
The Gartner blog on Windows Vista (the posting above is from it) is the Gartner blog I find most interesting:
http://vista.blog.gartner.com/blog/index.php?blogid=19
But they do have quite a few others available too:
http://weblog.gartner.com/weblog/weblogIndex.php