Total smartphones in use for Jan '10 is 42.7M, up 18% which yields 36.2M for Oct '09.
Running the percentages I get:
|OS||Nov 2009||Jan 2010||Change|
Note that new phones does not equal sales as old ones are retired, so it's the difference between sold and retired.
From this it seems that RIM is still leading the pack with Apple and Google doing similar business (my suspicion is that Apple is retiring a lot more phones and therefore selling more than Google). Google's business has accelerated dramatically since introducing the Droid on Verizon in November. The Nexus One has not sold well according to the reports I've seen but when it arrives on Verizon in the Spring there may be a bigger push to move it along.
Windows Mobile is declining pretty much as expected. They have done everything possible to reduce market share: let the old version stagnate, create new versions of the OS which can't run on the release hardware, and pre-announce a major incompatible version that is 6 to 9 months off. Expect more bleeding there before it's over.
Palm is a bit shocking - they are really suffering from being on a single network. They need a Verizon outing like no one else.