Just saw the first television advert, here in the UK, on the television channel, Sky 1.
It wasn't much. Just the guy who holds the Predator gun looking up fearfully at the Alien crawling above (the scene where, according to previous advertising, the Alien gets its head blown off). The screen then flashes away before anything happens, revealing the logo.
Have to say, it looks much better on a larger scale than the You Tube stuff.