I really don't know how to comment on this. If anyone out there isn't surprised, please raise your hand, so that I can point my finger at you and call you a liar.
Of course, promises are cheap, and "open" is a word that's almost completely empty in the corporate world, but the massive restructuring of the Symbian platform is radical enough.
It's comforting to know that the mobile blogosphere will give me answers to all the questions that this announcement raises within the next couple of days. So what are they going to say? "Facing ever sterner competition from Windows Mobile, Google's Android and Apple's iPhone, the key players in the Symbian ecosystem decided to take action, to lead to market to bla-bla"? Yes, probably. "Symbian finally succumbed to Nokia"? Yes, probably. "So how are they planning to make a profit?" Definitely.
Oh well, if this works out, it will have various interesting consequences. UIQ and MOAP will disappear (the useful parts that don't have counterparts in S60 will be assimilated, like a proven to be working outside the lab touch support). The mess that is Symbian will clash with the open source community, both technically and politically, and the Symbian Foundation will be the 666th company that come to learn that open source isn't about getting people to get engineers to work for you without paying them.
Can't be bothered to write anything more about this right now, but thanks to Nokia et al for an interesting press release, which I hope isn't a belated April fools joke.