Needs comments. People won't learn well from a demo that has no comments. But the actual demo looks pretty neat. I wonder how well it performs in multiplayer.
I'll clean it up and comment it in the coming days. Also, I've tried it in multiplayer. Performs quite well, really. You just have to make sure the players can't select too many units, like 2000 units at once. :o
[EDIT] wooaah

So much for that!