I've been watching
this guy's blog for a while. He is going to make a kit to transform a regular midi keyboard controller into an
isomorphic keyboard, specifically either a Wicki-Hayden or
Janko layout.
The advantage of these layouts is that you only need to learn one fingering for any chord*, and everything is played the same no matter what key you are playing in. You can reach much larger intervals with one hand - you have about 3 octaves under your hand at all times. It is also typically more compact than a linear keyboard with the same number of keys.
If anyone here is interested in getting one these kits, contact the guy. The more people who want them, the cheaper they will be for everyone, since he is getting the parts made in very low quantities.
* For example, an A minor chord is the exact same shape as an F# minor chord, and a C# major scale is exactly as easy to play as a C major scale.