There is a AMA with Gabe Newell on Reddit

https://www.reddit.com/r/The_Gaben/

I was going to stay up and try to get an answer to this question But to be honest the whole process is highly like just to up set me, and leave me unable to sleep.

If anyone is taking part, could you try an pose this question.

How many people will still ask about Half Life 3? XD

GabeN MMA

AMA?

Absolutely Morose Armadillo?

Albert the Musical Aardvark?

Armed Massive Aliens?

No, it's "Answer Me Asshole", obviously directed at Lord Gabe of course

I asked about them adding a method for listing owned DLC to their web API. Being able to detect DLC would make GOG Galaxy so much better (but please don't mention GOG Galaxy in this context - he might not take to the idea of spending development time and server load on promoting a competitor).

I mentioned steamgifts.com, a giveaway site that uses Steam's web API to keep you from entering giveaways for games that you already own (so that prospective givers get a measure of protection against the games they give being slurped up by resellers).

If you think the question is a good idea then maybe consider voting it up so that it's more likely to get answered:
https://www.reddit.com/r/The_Gaben/comments/5olhj4/hi_im_gabe_newell_ama/dck7dzo/

I wonder how many Twinkies that mother fucker eats in a day.

As many as he can get his hands on, but only when he's really high

FOUR DAYS AGO:

Proofs have been provided, excuses have been made.
As usual..

I scrolled through it earlier and I don't recall seeing that Q.

These were the highlights from the AMA:

On their new offices

Yes. We move into the new offices on July 22nd.

On Source 2

We are continuing to use Source 2 as our primary game development environment. Aside from moving Dota 2 to the engine recently, we are are using it as the foundation of some unannounced products. We would like to have everyone working on games here at Valve to eventually be using the same engine. We also intend to continue to make the Source 2 engine work available to the broad developer community as we go, and to make it available free of charge.

On Steam Support

Yes! We are continuing to work on improving support.

Since the last AMA, we've introduced refunds on Steam, we've grown our Support staff by roughly 5x, and we've shipped a new help site and ticketing system that makes it easier to get help. We've also greatly reduced response times on most types of support tickets and we think we've improved the quality of responses.

We definitely don't think we're done though. We still need to further improve response times and we are continually working to improve the quality of our responses. We're also working on adding more support staff in regions around the world to offer better native language support and improve response times in various regions.

On Half-Life

The issue with Half-Life for me is that I was involved in a much higher percentage of the decisions about the games, so it's hard for me to look at them as anything other than a series of things I regret. There's no information in my response about what we'll do in the future. It's simply easier for me to be a fan of things that in which I was less directive.

On Left 4 Dead

Products are usually the result of an intersection of technology that we think has traction, a group of people who want to work on that, and one of the game properties that feels like a natural playground for that set of technology and design challenges.

When we decided we needed to work on markets, free to play, and user generated content, Team Fortress seemed like the right place to do that. That work ended up informing everything we did in the multiplayer space. Left 4 Dead is a good place for creating shared narratives.

On Half-Life and Portal movies

Yep. They're coming.

On Half-Life 3/Half-Life 2: Episode Three

The number 3 must not be said.

On what he regrets about Half-Life

If you are involved in a game, everything ends up being a set of trade-offs. Anything in a game is a sacrifice of things not in the game. I just feel those more personally about Half-Life for a bunch of reasons. And Xen.

On possibility of a new IP in the Half-Life/Portal universe

Yep.

From http://www.valvetime.net/

Wooo-hooo! Five people now! Now those hundreds of millions of customers are served.

Has anyone asked anything related to Steam's quality control issues?