Call me nuts, but I'd like to see a sequencer/tracker program that combines the various ways sound can be created on a computer: midi with the built-in midi sounds, mod tracking with samples, softsynths, digital audio recording, maybe even the old FM/Adlib sounds all in one program, with midi input (for playing/recording) and a common sequencing/tracking interface. Effects and output to WAV/MP3 would be nice, too.
I know there are various programs that can do some of this, like Buzz, which does softsynths and mod tracking/sampling, but I'm not aware of anything that does it all.