Open source has two different kinds of developers, and both are necessary to the vitality of a project: individuals working for themselves, and employees of some company that uses open source in its operations. While the company employees are well funded, they are also directed or over-directed to work on the part that's important to their employer to the exclusion of all else. The individuals are more free to be innovators and architects, with a global view of the entire software project and eyes open for serendipitous opportunities. When both sorts of developer come together, the result is best-of-breed software like Firefox or the Linux kernel.
Both kinds of developers may choose the GPL: the commercial ones because they want to keep their competitors from running away with the program without sharing their own work, and the individuals because they'd rather function as equal partners in enforced sharing than as unpaid employees who give all they create as a gift to the big company.
GPL is also a commercial tool for companies like MySQL (now part of Sun Microsystems after a $1.1 billion purchase), who provide Free software to those who buy into the covenant of sharing source code, and profitably charge everyone else. And most important, GPL is what developers will use if they welcome Microsoft's participation in their projects, but only on the same terms as everybody else. GPL already is used to license around 70% of open source software. If such a thing can have an increase in popularity, Microsoft's participation in open source projects will cause it.
IBM has been a steadfast advocate of Apache-style licensing, fearing the terms of GPL, especially the need to share their patents if IBM becomes a partner. But now IBM finds themselves dancing a little too close with Microsoft after developing an open source strategy that was at least in part intended to combat them. Look for even Big Blue to become more friendly to GPL.
The Final Frontier
Whatever the effect of Microsoft's participation, their recent actions provide the last shot of credibility that open source will ever need. Even the most strident objectors have had to join or follow SCO into ignomy. Not because anyone forced Microsoft, but because a poorly-funded group with little central leadership and no employer in common out-competed them.
Microsoft's proprietary software paradigm focuses on the sales of software instead of the much larger economic value of using software. Discarding rules of property was known to be inefficient, but nobody realized, until computer collaboration became possible, that relaxing some of the rules of property could make such a collaboration work very efficiently. Open source repairs the economic breakage of proprietary software by making the users into the developers and collectively the owners. This works efficiently for software and electronic content like Wikipedia because the individual investment in creating such things as part of a group is low (a laptop, a net connection, someone's time, free software), and the value of using the result is high.
Western Union once owned interurban business communication, but stuck to Morse Code while businesses ordered telephones. Fighting open source today would be as sure a road to failure. The last holdout is legislation. Copyright and patent law have been created with only the proprietary model in mind. Their legislation is driven today by media conglomerates hawking an ever increasing need to combat "piracy," while the world at large has taken up the creation of content that can be shared without fear or shame. Nobody envisioned the Wikipedia, open source, Creative Commons.
Now, it's time for legislatures to wake up: national and international law must adapt to make the world safe for both open source and proprietary software development. Corporate and government purchasing policy must place open source and proprietary software on an equal footing. Open standards without royalties or discrimination, the true drivers of interoperability, must be recognized as the basis of fair and equitable IT policy everywhere. Only then will we realize the full potential of open source.