When I read that it plans to support PS3, X360, Windows, Mac, and also web browsers, I immediately thought “hmm… Unity?”, and lo and behold, the trailer indeed shows the Unity logo.
Looking at the video though, it looks more like tower defense + fps, not rts + fps.
UPDATE: Ok, properly hearing the video this time, I can say I’m stoked, I’d actually like to play this game!
Bloody awesome.
Edit: They have thread! http://forum.unity3d.com/threads/50747-Warsoup
Looks technically well done but not after game i could enjoy.
It somehow made me think of the rather sterile and boring HALO look. As for combining those genres, it probably more or less comes down to that the RTS defines the level design of the FPS. Dunno but if you want to play an RTS then Starcraft 2 beats the shit out of this game. If you want to play a FPS then the same applies for Half Life 2. But i can imagine that quite some people could especially enjoy it on the browser.