What's your budget? If you like the micro-korg and want to record music now, I'd suggest a synth. There are numerous options out there as well. Some good budget synths too. Here's a few examples:

-Yamaha MO-6/8: Stripped down versions of the Motif ES series--basically same sounds, ect minus sampling and a few other things. The MO-6 is selling for $1,199 U.S.

-Korg Triton TR: It has replaced the original Triton Le. More Wav Rom, black body, and a few extra goodies. Triton based sound engine. Like the MO-6 is to the Motif ES, The Triton TR is an affordable version of the larger Triton.

-Roland Juno-G: THIS IS THE ABSOLUTE BEST BUDGET SYNTH, just about to be released on the market (in my opinion). Roland should get an award for this puppy.

The new Juno-G has the body design of the retro Juno's from the early 80's. They have Fantom based sound engines, 128 voice poly, full synth engine with 4 element voice structure, can run 3 insert effects, HUGE back lits screen, real-time control, blah, blah, blah. However the HUGE HUGE HUGE advantage of the Juno-G is that it has a 4 track audio sequencer. Plus the standard 16 track 400,000 note midi sequencer as well. You can mix audio and midi very easily, and there are slider on the unit for real-time control of the audio tracks. This is going to be an awsome synth to the Roland arsenal. GET THIS! They're selling for less than $1,000

Squeak