The trick with Android, is that the apps aren't really Java. You code in Java, you compile to .class and .jar files and such - but then at build time the tools translate the java bytecode to some proprietary 'optimized' .dex bytecode. So you'd have to port their custom 'dalvik' VM to piggy-back off the Android developer community. Which I'd guess is proprietary, and definitely includes a good pile of libraries and interfaces that are.

Also, I get the feeling that their VM makes assumptions about the underlying phone architecture. At least insofar as chipsets, processing speed, bandwidth, etc. It's possible that even if Nokia partnered with the OHA that the NITs wouldn't match up with the required specs. (I'd be most concerned about the lack of video bandwidth and the still-untapped 3d capabilities)

So... I wouldn't hold out much hope. The best that we can hope for, is that someone will make a fast javaVM for maemo, and make it easy enough for Android projects to port to maemo.