Believe me, I've been around Video Editing for some time and I've seen and gave up on many programs, but VEM is the greatest thing I've ever seen.
However, there is a feature that would be important to me: sometimes there are times that I'd appreciate having more sources playing at the same time. For example, in the audio track you might want a soundtrack, and on top of that you would like to hear sound effects from the footage. These sound effects from the footage might require extra tweaking; therefore you would require having 3 (or more) audio tracks in the timeline(Audio 1, Audio 2 and Audio 3, respectively, or more).
I know that you could first of all spread the footage sound effects on the two audio tracks in the timeline, along with your video, then compile it, and then go into it again and add the soundtrack in audio track #2, but these are extra complications.
It would be nice, in the Timeline menu on the left of the screen, if there was a button permitting you to "add one more" audio or video track. Then, at specific places in the timeline, you could control which sources are active yourself by using the audio volume bars(ah-ha! there we go!).
Added support for additional video tracks would be equally appreciable.
Thanks for asking us about all of this!