Build No. 6001.16549 of Vista Service Pack 1 -- which Microsoft now is confirming as one of the "early, pre-beta test builds that were made available to a select group of testers" -- has made its way onto torrents all over the Web over the past few days.
If you're curious about what's in (and not) in the SP1 pre-beta, it's worth checking out APC Magazine's review. As Microsoft told selected SP1 testers, there are not any user-interface changes to write home about. But there are a few minor ones, according to reports.
Still no word on when the public Vista SP1 beta will hit, other than "shortly." And while a number of sites are reporting the final Vista SP1 will arrive in 2008, I'm still hearing that Microsoft is shooting for late 2007 for the final Vista SP1 code.