[James]

The SC models were just made for this game. Also in some of the levels, you can find (and control) certain SC units. Lots of easter eggs like that in this game.

Anyway, the ending for WC3 is exactly how the endings for Diablo II, Warcraft 2, and Starcraft were. They make them sort of like that, so you don't exactly know what happens and/or it sets up the expansion (which will have the spectacular ending).