IE9 for mobile seems very far behind in HTML5 compatibility. Is Microsoft going to use the excuse that "they are waiting to do things right", again, while everyone else plunges ahead?
Unfortunately, IE has always been behind and I don't think that's going to change anytime soon.
Of all of these features, the one I most want to see greater support for is Web Workers. I think this could be a huge boon for a variety of interesting client side work, and a nice complement to web sockets...
What are the use cases for web workers in mobile environments? I can't see any good reasons to be using up the viewers battery and limited prrocessing power that way other than for (maybe) backgrounding some of the processing for a web app.
On a non-mobile note: If you use my computer to run your map-reduce job without asking me first; I don't like you.