Microsoft has updated its Open Specification Promise page as of July 25, and it now says in the FAQ that the GPL is covered, including commercial:
Q: I am a developer/distributor/user of software that is licensed under the GPL, does the Open Specification Promise apply to me?

Most software developers have little interest in entrepreneurship, but an open-source software project will survive and thrive only by delivering value into a market (users) with business partners (contributors) and against competitors (other open and closed source software). If you want to run a successful open-source project, it helps if you consider the key questions that apply when defining a commercial business model. I'll expand on Chesbrough's and Rosenbloom's list of 6 themes to demonstrate why.

One of the key elements that helps to enable open source software applications to gain broader enterprise usage is the availability of commercial support options. In the case of the open source MongoDB NoSQL database, that commercial support is now coming from project backer 10gen.

Groovy++, the static typing compiler extension for Groovy, is to be released as open source under the APL2. The Groovy++ project started last year and at the time Alex Tkachman, project founder said Groovy++'s compiler "uses several pieces of technology, which our company uses and plans to use in our commercial products.

UPERTINO, Calif. (July 25, 2007) - SugarCRM Inc., the world’s leading provider of commercial open source customer relationship management (CRM) software, today announced the upcoming release of Sugar Community Edition 5.0 will be licensed under the new Version 3 of the GNU General Public License (GPL). The GPL is the most widely used free and open source (FOSS) license in the market.

Openads, formerly known as phpAdsNew, is one of the more successful open source development projects. Its online advertising software is used by many thousands of domain owners who want to make a profit on their Web content by selling advertisements.

Blue GNU interviews Al Chu, of the FreeIPMI project about their efforts to provide a free implementation of the IPMI specification for managing & monitoring hardware.

We are very pleased to announce that source code is now available for Project SocialSite (under a CDDL/GPL license) and the project is now operating as an open source project following the Glassfish governance policy. We're working in the open and welcome contributors of all stripes.

What will make a commercial open source project successful? Unfortunately, most people miss the two basic reasons why software succeeds or fails -- and doom years of development from the start.