C&VG have a interview with Doug Lombardi from the floor of the ECTS show

Here's a snippet

C&VG: What's the atmosphere like over at Valve Software at the moment? Is there an excited buzz or is it more knuckles to the grindstone?

Lombardi: Well, a little bit of both. You know, we hadn't shown the game, ever, and we didn't even talk about it - we didn't even acknowledge the fact that we were doing it for so long.

But after a while I think that put a certain taxing on the team, and I think bringing it out and showing it to yourself and to everybody else at E3 and now at this show, and seeing people write great things about it and saying, "All the five years worth of labour that you've been putting into this project was worth your time", that sort of energised everybody.

Also, the fact that the end is in sight, that just makes any situation better. When you can see the finish line, you always get that adrenaline rush to charge forward, and I think that's where folks' heads are really at right now

You can read the rest of the interview at C&VG