Fortune quotes Oppenheimer's Yair Reiner, who thinks Apple's patent infringement suit against Google Android and Microsoft Windows Phone manufacturer HTC was a warning shot meant to disrupt competitors' roadmaps:

"Starting in January, Apple launched a series of C-Level discussions with tier-1 handset makers to underscore its growing displeasure at seeing its iPhone-related IP [intellectual property] infringed. The lawsuit filed against HTC thus appears to be Apple's way of putting a public, lawyered-up exclamation point on a series of blunt conversations that have been occurring behind closed doors.

"Our checks also suggest that these warning shots are meaningfully disrupting the development roadmaps for would-be iPhone killers. Rival software and hardware teams are going back to the drawing board to look for work-arounds. Lawyers are redoubling efforts to gauge potential defensive and offensive responses. And strategy teams are working to chart OS strategies that are better hedged."

What changed?

"Top-tier handset makers continued to avoid implementing multi-touch, but Apple could safely assume that they were hanging back to gauge Apple's response to Motorola and HTC. If there wasn't one, the OEMs would likely read the silence as a green light, especially after Google also moved to enable multi-touch on its Nexus One phone.

It was likely in order to counter that perception that Apple began reaching out to handset OEMs in January and explaining in no uncertain terms that it was now ready to do battle–and not just on multi-touch. It was ready to press its case along a number of axes that had made the iPhone experience unique, from the interpretation of touch gestures, to object-oriented OS design, to the nuts and bolts of how hardware elements were built and configured."

He believes it's working, and might end up driving people away from Android and... towards Windows Phone.