I was at the JavaOne Technical Keynote for the demonstration and they've specifically optimized the Raspberry Pi to use the GPU for rendering the 3D graphics. Since a tablet is graphics intensive, this is why such a low-end processor seemed so performant ... it just doesn't take that much processor to handle touch events and tell the GPU what to draw or animate.
P.P.S. The coolest interface to their chess server was a chess-playing robot, also built around a Raspberry Pi and using standard hobby servos. I believe that project will also be open-sourced. (http://www.youtube.com/watch?v=pYLvTebauwE&feature=youtube_g...)
That calculator icon looks suspiciously like it could be a rip-off of the iOS 7 calculator icon. That said, looks like a wonderful project. I'm always struggling with the best way to access a headless Raspberry Pi. If something like this were a little cheaper it'd be great.
The tablet + ethernet port combo is a great idea... Are there any Android tablets that take high speed ethernet port adapters, making them suitable as servers?
My Viewsonic G-Tablet has a 10/100 ethernet port in the dock. It also has space for a miniPCI card if you want to solder something extra on. Either way, it can saturate my crappy internet connection.
Too much for what? If you want a top spec tablet, this isn't the project for you - this is about building something yourself, and to be able to do that at under $400 is something that was unimaginable a few years back.
Java is specific only to the interface. A cursory glance at the parts list shows nothing that wouldn't work on a Raspberry Pi in any other form factor.
Today you do, but Java9 will expand the idea of the modular JRE and allow you to tailor what's included. They were pretty clear that the road forward would see JavaSE and JavaME merge into a single project with different "profiles".
P.S. Project Sumatra was announced at last year's JavaOne and allows Java to run parallelizable code on GPUs. (https://wiki.openjdk.java.net/display/Sumatra/Main)
P.P.S. The coolest interface to their chess server was a chess-playing robot, also built around a Raspberry Pi and using standard hobby servos. I believe that project will also be open-sourced. (http://www.youtube.com/watch?v=pYLvTebauwE&feature=youtube_g...)