Another suggestion which I've heard before but wasn't really articulated properly is that the library (browsing) section should be adjustable in hight. Much like how you can change the width of your crates section. You should be able to shrink it and in doing so, enlarge your wave forms to run vertically down the entire screen. This will not only make beat matching that much easier (as VDJ has done) but will allow for more room for additional features such as more cue points and loops! With the popularity of laptop battles growing Serato needs more cue points for battling.

I guess that's two suggestions rolled into one.

Oh and also a third turntable that runs off internal mode and uses the mic thru as an output would be sweet...