About a year ago, the Austrian composer Peter Ablinger first presented his 'updated' player piano. Ablinger designed a hi res mechanism which allows him to create vocoder-like effects. The sound quality is amazing, Conlon Nancarrow would have loved it. Peter Kirn (Create Digital Music) investigated the case very thoroughly and found that the digital part was done in custom software developed by the composer in Pure Data.
More Speaking Piano pieces and documentations over here