Ask HN: Preferred mobile web frontend framework?

I'd like to target as many devices as possible, but Android would be at the top of the list (since we'll be building a native iPhone app).

I played around with jQuery mobile last night. I found the documentation to be a little light in some areas, and I couldn't get some things working like they worked in the demos. Is it still too early to make anything serious with it because it's in alpha?

Sencha Touch looks solid, but I've read that the Android performance isn't that great (maybe it depends on OS version). Plus, since it's tied closely to WebKit, I'm concerned about its ability to support WP7. Maybe I won't have worry about that for awhile.

I've also read jQTouch's Android support isn't good either.

Is there a framework that you would recommend? Is it better not to use a mobile frontend framework until something solid and diverse (like jQuery mobile is trying to become) comes along? What's been your experience?