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?
A: Absolutely, yes. The OSP applies to developers, distributors, and users of Covered Implementations without regard to the development model that created such implementations, or the type of copyright licenses under which they are distributed, or the business model of distributors/implementers. The OSP provides the assurance that Microsoft will not assert its Necessary Claims against anyone who make, use, sell, offer for sale, import, or distribute any Covered Implementation under any type of development or distribution model, including the GPL. As stated in the OSP, the only time Microsoft can withdraw its promise against a specific person or company for a specific Covered Specification is if that person or company brings (or voluntarily participates in) a patent infringement lawsuit against Microsoft regarding Microsoft’s implementation of the same Covered Specification. This type of “suspension” clause is common industry practice.
This is a major change. I haven't had time to figure out if there are any gotchas. None leap off the page. OOXML is under the OSP. And Sam Ramji has announced also that Microsoft has become a sponsor of the Apache Foundation. And they took the money. Andy Oliver confirms. Microsoft Associate General Counsel Richard Wilder explains a tweak to the OSP for Apache. Are pigs flying, or what?
Open Specification Promise: Microsoft is putting a wide range of protocols that were formerly in the Communications Protocol Program under the Open Specification Promise (OSP). This guarantees their freedom from any patent claims from Microsoft now or in the future, and includes both Microsoft-developed and industry-developed protocols.
We have established a clarification to the OSP that guarantees developer rights to build software of any kind and for any purpose using these specifications, including commercial use.
I am grateful to Andy Oliver, the creator and maintainer of Apache POI, for contacting me back in June with a hope that Microsoft could supply the necessary rights for POI. These include: rights for Office Binary document formats; Open XML; and the right to intentionally subset, have partial implementations, or defects in implementation of these specification. Andy offered his thoughts here.
Apache Software Foundation: Microsoft is becoming a sponsor of the Apache Software Foundation (ASF). This sponsorship will enable the ASF to pay administrators and other support staff so that ASF developers can focus on writing great software.
Jim Jagielski, Chairman of the ASF, had this to say about the sponsorship:
"We thank Microsoft for their generous sponsorship that goes towards supporting The Apache Software Foundation and the over 60 top level projects in use and development within the ASF," said ASF Chairman Jim Jagielski. "The ASF Sponsorship program is an excellent way for companies and organizations to show their commitment and enthusiasm towards the ASF and The Apache Way, and helps to ensure that highly innovative, freely-available and community-based/consensus-developed software can continue to flourish and thrive within one of the most successful and respected communities in Open Source. Microsoft's sponsorship makes it clear that Microsoft 'gets it' regarding the ASF."
Elizabeth Montalbano has details on PCWorld, including that the amount given to Apache was $100,000:
Microsoft on Friday expanded its support for the open-source community by giving money to the Apache Software Foundation, the first time it has given money to the long-standing open-source project.
Microsoft also said it is contributing code to support a PHP (Hypertext Preprocessor) project and committing to offer royalty-free specifications for Windows Server and .NET Framework protocols as part of its expanded support for the open-source community. The company announced its plans at the O'Reilly Open Source Convention (OSCON) now being held in Portland, Oregon.
Ryan Paul interviewed Apache Software Foundation (ASF) president Justin Erenkrantz, for ars technica:
Erenkrantz told me that Microsoft has been moving in this direction for quite some time. The company recently invited several Apache contributors to visit its Redmond headquarters for informal interoperability talks. Microsoft's recognition of the role that open source software will play in enterprise infrastructure comes directly from the top, he says, and isn't just confined to rogue elements within the company.
Microsoft's history of antagonism to and mixed messages on open source software will likely lead some critics to see the move as a potential trap. Prudence and scrutiny are certainly justifiable wherever Microsoft is involved, but it seems unlikely that there is any possible mischief in this arrangement; the governance model of the ASF just doesn't leave room for abuse.
Update: The Microsoft money is, of course, mentioned on Planet Apache, and here's a relevant comment:
Nick Kew — Apache: sponsorship vs membership
It seems Microsoft’s sponsorship of the ASF is being mis-reported as membership, for example here.
That is not merely wrong: it’s impossible. ASF members are not corporations, we’re individuals. We earn membership by what we do, not what we pay. So while it’s entirely possible for Microsoft employees to become members, the idea of the company doing so is a non sequiter.
The idea that this gives Microsoft any kind of influence in Apache projects is also nonsense. Apache projects are managed by individuals who leave behind any corporate affiliations when we don the Apache hat. The most a company can get is an indirect stake in an Apache project by employing or contracting with key developers, and (AFAIK) the nearest Microsoft has come to that is in their joint project with SourceSense.
 Membership of the ASF costs nothing, just as contributing to ASF projects doesn’t pay.
 At least, as far as the ASF is concerned, though Microsoft’s attitude towards the common good may have to come quite a lot further. The biggest shift may come if they want badly enough to hire someone who insists on their right to participate in opensource projects.
Update 2: Bruce Perens reminds us of some history, Microsoft's 2002 Plan to Sue Apache:
Lest we forget, below is the memo detailing Microsoft's past plan to bring lawsuits against the developers of popular Open Source software, including Apache, Sendmail, Samba, and Linux. This came out while I was still at HP, but of course I was under NDA. It was a particular hardship for me: there was never any question when I was hired at HP that I was an Open Source representative first, and an HP employee second. And then I got stuck with keeping the secret of Microsoft's plans to bring suit against Open Source developers, for years. All of that time, I felt that I was being disloyal to my own community. This finally came out after I was long gone from HP.
Microsoft backed SCO's lawsuit after releasing this information to HP.
Linux.com article containing HP memo.
And before we get too dewey-eyed, let's not forget Software Freedom Law Center's analysis of the OSP.