Yeah they have three DJX keyboards now. The djx-1 is considered the professional version of the three. The djx-2 is a stripped version of the djx-1 and is intended for the novice keyboard player who just wants to pound on a keyboard.
The DJX-2B is similar to a groove box. Lots of djx users are planning to take a look at it. However, the reviews I have read all say that the box really can't be used very effectively for live performance. However, it will be interesting to check it out in person.
Glad you found the user site helpful. We will be adding more content, software and technical information as it becomes available and we have time. Right now we are swamped with tons of more things than we have time to add presently. Especially, since we are trying to collect as much djx-1 information before Yamaha and others pull it off their website in order to make way for the Djx-2 and djx-2b.