BWAPI Replay Tool
With new tool on the scene, so called "BWAPI" we can do so much more, for example: How much player has units (and specific unit like Mutalisk), what unit is hatching, HP (health points of an unit), idle Larva number, macro/micro rating, worker stats (and total), how much workers does mine and whole new system of showing Build Order that is used.
It seems that you can also use various commands to make your replay viewing experience even better and everything is put in such manner that information is visible but still - it doesn't nag your eyes or make game unwatchable.
And if you are good programmer maybe you can redirect your browser to BWAPI's main page and use source code of this tool to enhance it a bit more and make it better?
Replaypp.googlecode.com - Download BWAPI
iCCup.com - Source
Replaypp.googlecode.com - Main project page of BWAPI tool