When HP announced that it will stop working on webOS and exiting the mobile business, I was disappointed to hear them say that they will not be selling the mobile patents, and will instead hang on to them. That was around the same time Android OEM's were getting hit by patent lawsuits and Microsoft trying to squeeze the door on everyone to make them pay for their patents.
Google was in search of buying some quality patents to defend the Android OEM's back then, but they couldn't find too many, other than Motorola's patents, for which they paid a lot, and much more than their real value. The problem with Motorola's patents was that they weren't too related to smartphones, but to normal phones from before.
The most relevant smartphones in the industry were Palm's, Blackberry's, Nokia's, and of course Apple. Apple may not have thousands of them, but they have a lot of touchscreen smartphone related ones, so that makes them pretty dangerous when everyone is making touchscreen smartphones.
I would've liked Google to get some patents from Palm, Blackberry or Nokia, at least. Nokia seemed the least likely to sell their patents, though. They may be more likely now, once the phone division separates from them, and is acquired by Microsoft, but so far they've stated the intention to license them out. Blackberry is selling them now, so Google may want to get some of them.
Bloomberg is reporting that HP is also interested in selling its patents now, so that's another opportunity for Google to buy more relevant smartphone patents, or at least negotiate with Blackberry over theirs. Palm also had some newer patents around webOS, which was also a new and modern operating system meant for touchscreen smartphones, so they may have a handful of patents that are even more relevant than Blackberry's.
Google should definitely look into acquiring a bunch of them from each company, and try to pick the most important ones, rather than buying all from each, unless they can get them relatively cheap.