I would love to see an arranger that moves it all one step further...
By combining a typical arranger, KARMA and the Matrix from Ableton live intoo one big engine... A style would have like 8 tracks with 8 parts... top line buttons would switch all tracks to the next part... But you could also switch inidividuall style tracks. Normall intro/fill/begin would still be available... but also Karma fills, and they would play ontop of a style.. Next to the system should also allow audio fyles that can be transposed(elastique) to reflect the right chord.
Next to i would love to see more options for direct controll over the sounds.. some knobs would be highly appreciated as well as a ribbon controller..
Most important would be full master keyboard functionallity, which would let you assign every button and/or controller to any external function you would like..
An application that would function as /VST host/VST plugin/extensive editor/ on a remote computer... most top model synths allready have this for years and years.
... and every good arranger should have both 61 and 76 key versions, but tghat would not be a new feature