You really can't avoid native execution if you want to really push the frontiers on these devices. And because these are such small devices even lone developers can really push boundaries and make money and a name for themselves. But the second you start blindly "optimizing" their products, bad things happen in spades.
In my opinion implementing a VM purpose built for a specific language spec is, was, and ever shall be a mistake. Sun was wrong to do it with the original JVMs. In this regard at the very least Dalvik is ahead of the game. The problem of course is, however, that implementing any VM at all on an embedded device results in crap performance from all apps executing through it. The reason Apple chose to remove multitasking and force C# down people's throats was simply because it's the only way to develop an application that is sturdy and fast on an embedded device today. Claiming it frees the developer from having to optimize their code betrays your ignorance of developing on embedded devices.
In my opinion implementing a VM purpose built for a specific language spec is, was, and ever shall be a mistake. Sun was wrong to do it with the original JVMs. In this regard at the very least Dalvik is ahead of the game. The problem of course is, however, that implementing any VM at all on an embedded device results in crap performance from all apps executing through it. The reason Apple chose to remove multitasking and force C# down people's throats was simply because it's the only way to develop an application that is sturdy and fast on an embedded device today. Claiming it frees the developer from having to optimize their code betrays your ignorance of developing on embedded devices.