Ha, beat me to it, there, Gary and Bill.

Hi. Got onto this forum late. Fascinating discussion. I wanted to offer an opinion that there IS an arranger keyboard of sorts for young musicians performing modern musical forms like electronic dance music, hip-hop and the like. It is Casio's XW-G1, and to a lesser extent the XW-P1. No, these keyboards won't do automatic accompaniment but they do come loaded with the equivalent of 100 rhythmic loops and patterns, each with eight variations, for the built-in step sequencer, 100 preset phrases for the phrase sequencer/recorder and 100 preset arpeggios. The sequencer can be "played" in real-time using the keyboard's nine sliders and a series of buttons. It's all very much in the spirit of an arranger keyboard but for more electronic kinds of music.

Nigel posted a link in the Casio forum to a review by Craig Anderton from last year. Check it out and see if you agree.