no evidence they have dropped out of the market, it just looks that way now because the latest roland discover 5 has no styles aboard, but relies on a system of modifying various parameters of midi files in real time. Thus you have midi files you have loaded onto smart media cards, max 128 MB at the moment?

Maybe it will be more interesting to try than it sounds, but what will the "pros" say to the "arranger musicians" who no longer even play left hand to generate their own chords from some one else's created backings, but just play along with midi files?