I'm looking for a remote 2 1/4 format radio too. There are several on the market (Becker, Funkwerk, Xcom) but there has been virtually nothing new on this scene in the last few years.
There is a market for these - quite a few aircraft are very tight on panel space both on the front face, and more importantly in depth behind it. 2 1/4 remote heads solve this problem very nicely. They're great for tandem aircraft too, if you can have a master and slave setup.
Hopefully Dynon (and MGL who are developing one too) will tempt us with more info on release dates, specs, etc soon!