I'm not sure if it supports replays, or how much effort that would be to add, but if it can, you could extract huge amounts of metadata like build timings/orderings and whatnot.
[Edit: and of course, if you can render to a virtual screen, maybe there could be some way to run headless or multi-instance on a single box]
If you can get the suitable video player controls, it'd be fun to integrate it with an interactive timeline something like SMILE[2] to show significant events throughout the game (first discovery, first unit death, 'interesting' (say, involving more than X units or Y diversity of units)
That SMILE is effing sick. I'm def gonna work on integrating that...WOW