You have to wonder what is going on with NASA. They had updated their page to allow downloading of the SDK and then they pull back and post this:
The Java SDK will be available by the end of today. (May 10)
Um guys, the cat is already out of the bag now. Anyone feel free to download a copy of the SDK right here.
Update - Trust me, you probably don’t want to download it right now, I can’t get all the tiles to load and even then it is so slow. Probably why they pulled it.