my ideal tracker would have:
its own native synths in which every parameter could be controlled by automation
smooth high resolution drawable automation (curves, lines and points)
a really good fine detail sample editor with the option to move a small looping section backwards and forwards by automation
a DAW-like song timeline in which long samples could be layed out alongside normal tracker patterns (being able to record vocals, guitar, keys whatever in one take without splitting up the recording into pattern sized chunks)
very low latency, no lag when recording.
it should be portable and make use of both gamepad style controls and touchscreen controls. For this i guess it would have to run on something similar to psp vita. (the touchscreen controls are awesome for recording movements of sliders into automation, laying down a beat on virtual mpc style pads or recording a melody on virtual keys.)
it would be a complete in the box solution to making electronic music and then recording instruments like in cubase or on a four track.
it would have to have decent quality inputs and outputs.
anything that could be controlled by automation could also be controlled by pattern commands in a tracker style pattern editor. for when you dont want smooth changes between values but want to jump instantly from one value to another.
infinite tracks
some kind of video editing (haha going to far), must be portable system
high quality render to wav for whole song, individual tracks, individual patterns.
everything on the sunvox and renoise todo lists.
its annoying for me that a alot of chiptrackers that are based on old game systems are bound to frame rate for their speed calculations (so i can never get perfect BPM from nanoloop, lsdj or famitracker, for example) so my ideal tracker would break from that and have perfect BPM.
it could also run on a high powered tablet with a large screen but with one of those gamepad addon, slide over things bit like the wikipad