I like the game, it does really feel like they left room for an expansion though.  The only thing I was really disappointed with was the lack of upgrades.  It seems to me that Tiberian Sun had even more advanced technologies (GDI). 

 So I'm really thinking that we'll see an expansion pack to C&C3 that will introduce a lot more of the advanced stuff that people were looking for.  Maybe the original C&C3 game was meant to be a throw back to the classic, and maybe it's in an expansion that we'll see some very different stuff.

Some of you will probably complain that an expansion means you'll have to shell out more cash, but those same people will probably buy it anyway.  Either way stop complaining and just enjoy the game.