2) Programatically, they've got Qt now, which is easily comparable to Cocoa, and doesn't require devs to learn a new programming language.
I haven't looked at android's, nor have I heard any commentary, which usually isn't a good indicator.
Out of the 3 (or 5, +palm +msft), it's going to come down to device/network/developer relations. This market's still pretty open, and nobody's really doing a great job on #3 yet.
Then again, I'm wondering if the portable app market's nearly as important as is commonly thought; perhaps the web really has changed this game permanently.