That's a regular Microsoft Natural Keyboard Elite. It's a split key format, for ergonomic purposes (read: prevents carpal tunnel or repetitive stress injuries of the wrist). It's considered one of the best split key keyboards, with nice heavy clicky action (for a membrane based keyboard). It (the whole series really) is consistently ranked as one of the best keyboards.
It's an off the shelf product, not a specially designed prop.
Source: looking at the one ten feet to my left.