The problem with Flash is that it's <i>really, really</i> slow. For most web-browsing PCs there's more than enough power under the hood to spare to account for the slowness of Flash (even then, Flash is sluggish on most machines, just not enough to be <i>really</i> annoying).<p>On a phone or other slow-ish device, I cannot imagine how it could even hope to run.<p>Look at the Palm Pre - a very good example of trying to run non-native code <i>all over the place</i> in a mobile device, and the whole thing grinds to a halt. Multi-tasking on the Pre is a bit of a joke because of it - sure you can <i>do</i> it, but not if you wanted some semblance of snappiness in your UI.