At least Gabe will apparently make the most amazing entrance ever.
Fair warning: This video is only slightly creepy. That's if you consider a crazed Half-Life fan biting his friend's ear off to be creepy. Let's just say it seems like the creator took some inspiration from David Firth.
And for the record, I'd be very happy with a new Left 4 Dead.
Gabe Newell at E3 2012 [Reddit]