Actually, Casio did make an arranger module back around 1989, called the CSM-1.

Primitive today, but pretty cool back in the 80's.

I had one here that came with an old electronic accordion I bought at an estate sale.

There are gaps beginning in the arranger market, left by Roland, for one, and rumor has it that Casio has plans for filling them.

Apparently it's an arranger that will sit between the MOTL and TOTL...

For example, Yamaha has the S910, and then there's a big price jump to the Tyros3.

Casio certainly has the clout to pull it off, if they want to...they made great pro synths (CZ-1) and samplers (FZ-1) some time ago.

I've heard, from a pretty reliable source, that they are working on something similar to Korg's DNC....and it's for a new arranger, and perhaps, a digital piano/arranger.

Time will tell.