Having spent a great deal of time using Toshio Iwai‘s Electroplankton, I am very, very much wanting his latest project, created with Yamaha: Tenori-on.
Sir Ranjit Bhatnagar has also kindly hipped me onto Monome, based out of Philadelphia, who are handcrafting a similar device for sale soon (check out their vids).
O Christmas time, how I wish you would come early this year.