My feelings exactly royandreno.
I had hoped Arrangers might evolve a little more than they have, but other than better samples and better storage capabilities, I don't see a lot of significant changes as new models arrive to replace old older ones.

I had hoped someone would be innovative enough to incorporate similar technologies used by Steven Kay in Karma, but with better control so that a user had a choice between using the locked patterns that exist now and algorithims like those used in Karma. It never happened, and I don't see any signs that it will.

Rayzoon's Jamstix has exactly the type of features I would like to see in a new arranger. It lays down drum tracks instantaneously as you play, and it can create them interactively, based on midi or audio input, or it can lay out predetermined patterns, or a combination of the two. A bit surprisingly to me, from the demo I tried, it works quite well. That is exactly the kind of functionalty I hoped to see an arranger have, but I just don't see Yamaha, Korg, or anyone else doing it anytime in the near future.

AJ