Let's be clear: Microsoft's pledge is not a blanket covenant not to sue [UPDATE]
Microsoft is not giving away the farm to open-source developers.
Microsoft did agree not to sue open-source developers, but it had already promised that before. [NOTE: My memory was a little fuzzy on this. See below.] It also said it would provide access to its IP to commercial open-source companies at fair rates, which is also not news.that Microsoft was covenanting "not to sue over open source." This, unfortunately, is only half-true.
In other words, there is
no some news in Microsoft's announcement as it pertains to patents and open source. None. Or very little.
UPDATED: What I failed to mention was that Microsoft's original pledge was more constrained to developers in the OpenSUSE.org community and to "non-compensated developers." In other words, developers too poor to worry about. :-)
So, the fact that Microsoft is now opening up to any open-source development and non-commercial distribution is important, though not significantly more than it originally promised. It's still designed to limit non-commercial distribution, which is effectively what the original proposal called for. I understand Microsoft's stance on this. I just wish that it would change it.
Instead, the really big news is Microsoft's commitment to open APIs and open protocols. That's the takeaway. This announcement really has
nothing little to do with open-source companies or developers, except inasmuch as they want to better interoperate with Microsoft technology (which many of us do because our customers require it).
It's great news, and it's big news. My company has been seeking this API and protocol information for months (years, really). But Microsoft's pledge doesn't obviate the need to negotiate patent royalties, if required, with the company. I do know, anecdotally, that Microsoft is offering very low royalties for these patents, and it's also promising to more clearly delineate the boundaries of these patents.
But this is not a free lunch for open source. Sorry.