By "run naked on the processor" I mean that the JVM is the only software that runs on the processor - as is the case with embedded apps.

To actually see anything on your display, a whole truckload of library code needs to be implemented; take the simple case of Swing (which ain't that simple) - for a basic Swing window to visually appear on your N900, there needs to be bindings through to the hildon layer....ie. the JRE needs to be built - not only for the ARM platform - but also for the Maemo environment it will interact with. Not only that, but the limitations of the Maemo5 GUI will have a significant impact on how those bindings are implemented. Coding Java apps for Maemo5 will be a tad more awkward than for good ol' 'Doze or X