While the smartphone wars continue across an ever-shrinking set of carriers, the legal battles around the Android platform are only growing. Yesterday, Microsoft filed a patent-infringement suit against Barnes & Noble for its use of the Android operating system in its Nook digital reading platform. That, coupled with the continuing litigation between Google and Oracle over the use of Apache Harmony libraries in the Android operating system, cast a shadow on the future of the platform.

Microsoft’s lawsuit against Barnes & Noble alleges that the Nook infringes upon a number of its patents. The suit includes Foxconn and Inventec, both of which manufacture portions of the Nook.

In a statement issued by Microsoft, the company referenced its existing patent licensing agreements with Android handset maker HTC. Microsoft claimed it has tried to bring the Nook into compliance through patent license negotiations with the three involved parties. This lawsuit is a result of the failure of those negotiations.

Meanwhile, Silicon Valley is still wondering what will occur in the legal battles between Google and Oracle. Oracle’s suit is moving forward in Californian courts, not in the typical patent battlegrounds of Eastern Texas.

Florian Mueller, an intellectual property consultant and blogger, said that the choice of venue was likely intended to lend legitimacy to Oracle’s claims. “I think it made a lot of sense to have this case in California,” he said.

“Companies like Oracle are very likely to sue in jurisdictions that don’t have this patent-troll-friendly reputation that Eastern Texas has. They want to show they have a real commercial issue, that they are real innovators and they aren’t being trolls.”

Even though the patents in question in the Oracle case are allegedly infringed upon by the Apache Harmony project, Mueller predicted that Oracle wouldn’t be running off to sue the Apache Foundation, nor IBM, which also uses Harmony libraries in some commercial products.

The Apache Foundation is safe because it is a non-profit, so litigation against could make Oracle look bad, he said. But with IBM, he said the two companies are obviously cooperating elsewhere and have large patent portfolios with which to horse-trade.

“IBM has the biggest patent portfolio in the industry. There would be a cross-license deal [with Oracle],” said Mueller. “That’s different from Google: Google brings pretty much nothing to the table in terms of what Oracle needs. Google has a lot of patents in search, but that’s about it. Why would Oracle need those?”

But even with attackers on all sides, Peter Vescuso, executive vice president of marketing and business development at Black Duck, said that few companies are asking Android legal issues. Black Duck sells a tool for device manufacturers that keeps track of the changes within the Android operating system, and he said he has heard few questions about the legal ramifications of lawsuits against the platform.

“I haven’t seen [concern],” Vescuso said. “We already have many customers that are device manufacturers who already use Android, and they have expressed surprisingly little concern about the Oracle/Google Android lawsuit. I would have guessed we’d have customers looking at that, but we haven’t seen one inkling of [concern].”