I think it was last years GDC trailer which shows an operative or maybe it was an engineer being hunted by a guy with 2 machetes, he doesn't even shoot at the operative once, he just waits to catch up to him and stabs him, I also read somewhere on this site that there are non gun weapons, are those just grenades and explosives or do you think there may be twin machetes and/or other melee weapons?

Yeah, we've been through this, so I'm gonna say this as conclusively as I can.

2 melee weapons, gun butt and knife, knife only available when pistol equipped.
No duel wield of any kind.

That's just a trailer. Oh and yeah, there are grenades, mines, etc.

http://www.gamesas.com/index.php?/topic/1154289-list-of-what-you-cant-do-from-the-trailer/page__hl__things+you+trailer

Complete list.

I feel like SD is showing lots of things in trailers that you cant do in the game itself. They should chill a bit.

It was really just the Cinematic trailer that did, but it's supposed to be Cinematic so gameplay isn't what's supposed to go into one of those.

It was one cinematic trailer, quite a long while ago.

2009.

It's a cinematic trailer for advertising, almost every game looks better in cinematic trailers.
There's also a topic with things you can't do from the trailer. I'm not linking it from my iPod, takes too much tIme.

You already did link to it on the 2nd

Dysfunkshion is correct, this is a game cinematic rather than in-game content, and it's quite common for cinematic trailers to include things you can't actually do in the game. Since there's already a comprehensive thread about this topic let's continue it over there.