Mary Jo Foley triangulated a few things this afternoon to float a possible launch date of Windows Vista for business customers. Microsoft's officially maintaining the November for business, January for consumers schedule.

Foley -- longtime Microsoft watcher, now blogging on ZDNet as "An Unblinking Eye on Microsoft" -- cites Brad Goldberg, general manager of Microsoft's Windows Client Business Group, saying that Microsoft has one more large test release of the operating system before, in Foley's words, "it's soup."

She sees Nov. 9 as a good candidate for the business launch and points out some fairly compelling reasons: Microsoft's tendency to launch products on Thursdays and a big event in Brussels geared for businesses scheduled on that date. Bill Gates is presenting. The promotional stuff is all about "ready for a new day."

On the other hand, Brussels could be viewed as an odd place to launch the operating system. It's the seat of the European Commission, which is engaged in an ongoing antitrust battle with Microsoft that has entered a new chapter recently over concerns about security features in Vista. (See thorough coverage from CNet.)

Still, we've marked our calendars.