I've been thinking about the eKo a lot, and it is the potential that really has my gears going. While it is not an arranger as we know it, it could be with the right software. Something like Jammer Live and/or a program which imports/playback Yamaha/Roland/Korg styles would do it (although I'd like to see arranger software that is on par with the Tyros come out).

Since the control surface "modules" are interchangeable, arranger-type interface features should be easy to setup. It's even possible that a future option might allow for drop-in internal speakers (if OpenLabs doesn't offer such options then there's a market for third-party add-on makers to create specific arranger control modules and speakers modules).

We haven't seen the back panel of the eKo yet, but I assume it's like a PC. If so then that means there is lots of potential for setting up audio and midi interfaces plus any kind of digital I/O you would like. By adding an audio card such as the Yamaha SX1000XG you would have an XG hardware synth in addition to whatever software synths you wanted. Also video cards would give you the potential for multiple external monitors.

With the diversity of the PC accessory market, there is no end to the things that you could beef up this instrument with. Too much fun...