So, Nuclear Dawn is going to blend RTS and FPS in titillating ways that no game has pulled off before. It's set in post-apocalyptic real-world cities, and it features a carefully balanced class-based combat system that will rain fiery strategy on the spam campers and tea-baggers out there.
It takes more than awesome to make a game, however, so here's a more detailed look at some of Nuclear Dawn's other features: http://www.nucleardawnthegame.com/blog/post/102/nuclear-dawn-fact-sheet-ii-featured-features