I have been curious about the Raspberry Pi for quite a while, and I finally succumbed and acquired one when I heard that there is now a boot image that has Sun^H^H^HOracle Java preinstalled.
Running a Java EE server like Apache TomEE was then simply a matter of untarring the same binary distribution that I use on Intel and AMD machines.
Preliminary speed measurements indicate that Java code runs about 20-40 times slower than on a single core of a 3 GHz Opteron 4284 "Valencia".
Now I just need to figure out something fun to do with those GPIO pins...