I agree, modplug would be great as a vst instrument. I primarily started making music in modplug, but eventually made the jump to a cubase/fruity loops combination. Being able to open FL in cubase has been a godsend, I can run my sequences and record guitars or vocals at the same time, never rendering my sequences to .wav. In order to use any of my old modplug songs, I have to:
1. resequence everything from scratch in fruity loops; OR;
2. render all of the tracks, ONE AT A TIME (not fun when you have 60+ tracks running) to wav, and move them into cubase. (this also seems to eat up more memory in cubase, as I'm running WAY more lengthy wavs.)
Also, both FL and ModPlug have their cool points, and being able to run them simultaneously from cubase would be positive, taking advantage of both interfaces.
So, when will we see a VSTi feature for ModPlug?
Oh, and Fruity Loops IS a stand alone application that can be used as a plugin for cubase, Sam_Zen. It's actually really cool!