They'd also have to alleviate the UX problems with Flash - most notably the fact that it's a development tool for mouse-based UIs, not multitouch UIs. It's not

They'd also have to alleviate the UX problems with Flash - most notably the fact that it's a development tool for mouse-based UIs, not multitouch UIs. It's notoriously difficult to design for an environment in which you don't know whether the user can mouseover or not, whether they can use multitouch gestures or not, whether there needs to be scrollbars vs. draggable content, and you don't even know if the pointing device will be a pixel-accurate mouse pointer or an inaccurate finger.