The prevailing opinion on whether Microsoft will follow its most recent posturing on the issue of alleged violations of more than 200 of its patents in various pieces of open source code with actual litigation seems to be that it won't -- and never intended to do so.
The most immediate reason: It's re-raised the issue in order to speed up cross-licensing deals similar to the one it struck with Novell several months back. The pressure is on both because of the open source community's general disdain for Novell's deal with the devil and because it's expected that version 3 of the GPL, due in July, will include revisions that will forbid distributors of Linux from such arrangements.
Makes sense at a basic level: Such deals would be lucrative; patent litigation would not.
Not to mention the argument, well described at Ars Technica, that the Open Invention Network (OIN), which is the holder of patents on technologies crucial to many of Microsoft's own proprietary products and uses them to staunchly defend the "Linux System," would retaliate against Redmond-initiated litigation by suing the company for misuse. This assumes that Microsoft is actually violating one or more of those patents.
Just like its claims against Linux, et al, this is only an assumption at this point. But even if that assumption proves unfounded, somehow, the article suggests that the power of the threat will work in both directions, and Microsoft could be shoved into disadvantageous cross-licensing agreements requiring it and OIN to allow cross-use of patented technology. And that is exactly what OIN would like to see happen.
Thirdly, a recent Supreme Court ruling on a patent case has legal experts saying that an "obviousness" or "common sense" test will make it both more difficult to obtain patents and, more importantly, to defend existing patents. Would Microsoft be likely to want to be part of a costly and potentially brand-devastating test case?
And looking forward, there is bipartisan support for patent reform legislation introduced in Congress, aimed at reducing the number of patents of questionable validity awarded by the U.S. Patent and Trademark Office, reducing awarded damages, and directly addressing the patent trolling issue.
Short-term, the cons of Microsoft litigating to prove patent violations are daunting; middle-term, they're worse; and long-term, cumulative repercussions paint a scenario in which taking legal action seems ill-advised, indeed.