The whole operating system market for the mobile phone market appears to be in a state of some flux, with companies declaring alliances, buying each other and scrapping stuff all over the place. The last six months have been pretty unprecedented.
We'll take it as read that Apple, which has always said it will be the only company making iPhones and basing them on its iOS system, has been completely consistent (smart money now appears to be saying iPhone 5 will be announced formally in October rather than December, by the way).
Meanwhile HP has all but scrapped WebOS, only a year after it bought it in from Palm. A change of CEO and consequently a change in direction and HP isn't interested in mobile devices any more.
The Android-powered market is holding steady and growing, but once it sinks in that Google really does have its own handset maker following the acquisition of Motorola the other companies may find it a less appealing partner. Certainly Samsung is well advised to stick to its own operating system, Bada, for the moment.
BlackBerry's market share has been falling but at least, like Apple, it's steady and knows its plans for its systems. Personally I wouldn't want to second guess what the others will look like a year from now.