[Minneyar]

It's an interesting possibility. It's only natural that a JVM for the DS would be have to built around the hardware, but it's the same with every other platform -- VMs for Windows, OS X, Linux, Solaris, etc., all have to be built specifically for their operating system, even though they're all capable of running the same byte code.

In order to run on the hardware within the constraints of the DS's processing and storage capabilities, it would probably need to implement the J2ME specification. It would probably be functionally similar to the JVM available on cell phones or PDAs, with the only real difference being that it has a second screen available.

A JVM for the DS would definitely be very cool, although I think it would be more useful for things like porting applications from cell phones or PDAs or rapid application development. Something like a web browser, calendar, or e-mail client would be much easier to develop in Java than C, although I would imagine that games would still be coded in C for performance reasons.