I bet you thought that huge thing behind the space marines was going to be a giant worm, or an alien bug or something! Nope, it's an even bigger space marine, with a gatling gun the size of a mid-grade sea vessel. Some very Halo-y piano in there at the end, too. No gameplay yet, but I guess we'll get to see that at E3.
Honestly... CGI trailer have stopped impressing me for a long time.
If you to sell me a game show me the game itelf, show me how good the gameplay is, show me how nice the vissuals are, show me it has an interesting story with in game cutscenes.
CGI can make any crap look good.
Not to mention that these sorts of trailers are expensive to make, I'd rather they have 10 extra mission in the game rather than a trailer based on the game that shows me nothing about game