Well theoretically it will be possible, but I don't know if they've started on the iphone runtime yet. Pretty much Francois (and Yves?) has to make an interpreter that will turn your MFA into something the iPhone will understand. Now how the uploading and Apple developer licensing will be set up is beyond me, but I wouldn't be surprised if all you had to do was select iPhone from the application type dropdown and build. Though it may be required that you start a special MFA that is designed for iPhones, I don't know...
It's all up in the air for now! You can't build iPhone apps yet but it's on the horizon.
Don't expect "Export as iPhone app" to be bundled with any build upgrade ; I'd expect it to be pretty expensive if it becomes a reality. Even for a Clickteam product. Unity is around £1500 I think.