Wow. Motorola, NEC, DoCoMo, Panasonic, Samsung, and Vodafone announced that they're banding together to create a unified Linux-based operating system for mobile devices. The group says it will create a unified set of APIs, but said nothing about user interface, so presumably they hope to differentiate from one-another at that level. The UI is pretty closely tied to the APIs, so I'm not sure how they will pull that off.
Anyway, this is potentially a major challenge to the Windows Mobile and Symbian worlds, as this new Linux would presumably be free of charge. I think it's also ominous for PalmSource/Access and TrollTech. It'll be much harder for any of the mobile OS companies to charge for their software if there's a practical free alternative. (Speculation: If Motorola had succeeded in buying PalmSource, would they be donating some or all of Palm OS for Linux to the new consortium? We'll never know.)
I think it's increasingly clear that OS plumbing is going to be a commodity in the mobile space; if you want to make money, you need to focus on the upper layers of the software.
On the other hand, the devil's in the details. As Symbian discovered, it is incredibly difficult to serve several different masters. DoCoMo can keep the Japanese vendors in line, but Motorola and Samsung are mortal enemies and I am very surprised to see them in the same camp. Maybe their mutual fear of Nokia and Microsoft trumped their dislike of one-another, but we'll see how long that lasts. Will the Linux partners band together to pull down the proprietary OS's, or will they use the knives on each other? Either way, the next couple of years should be a very entertaining.