You answered your own question

I've never seen that video before and to be honest it looks more like a Rockstar showreel rather than an AONO trailer. It probably only has about 10% prodigy content.

As for the song, I've no idea. Sorry.

You're correct. It's a short Rockstar promotional video. It's not a promotional clip for The Prodigy specifically or for Always Outnumbered, Never Outgunned. You see a lot of none Prodigy things coming by in this short showreel as well. It was made even before Always Outnumbered, Never Outgunned got released. The music which you hear is also not by The Prodigy. What the music is though, I don't know either. I would suggest asking Rockstar.

Very strange promotional video. promoting lots of prodigy, about half of it is pics of the memebers, 'always outnumbered, never outgunned' written everywhere, some footage from the always outnumbered never outgunned demo mix, even the helocopters from the old prodigy site, and then the rest seems to be video game related companies (atari, ps2, westwood, rockstar) and like one shot for perhaps a second promoting greenday.

random as hell.

oh, and something quite short about viral killers aswell, which i have no idea about.

Don't know the tune but thanks for the download!
Hadn't seen that before.