[Qz]

A similar thing happened many years ago when an early version of Half-Life 2 got leaked. Reaction was tepid at best, Valve went back and basically re-made the entire game (delaying an already delayed game for substantially longer), but ultimately resulting in an award-winning game with an amazing (for the time) new engine. The pirating of the leak was of course highly illegal, but you could easily argue that Valve wouldn't be where they are now without it. (Half-Life 2 also contributed to the success of the Steam download service, another first for the company.)

[83457]

My recollection of this is...The person who leaked HL2 actually hacked into Valve's network and could not find anything that could be considered a game, just a bunch of tech demos and assets (I downloaded and played the E3 demo). He essentially announced that Valve was lying to the public about their progress on HL2 right before the originally scheduled release date and delay. I believe Steam was announced before the leak, and released well before HL2 release.

[electromagnetic]

It was released well before the HL2 release, because I remember having HL2 pre-downloaded for day of release.

[Maxious]

Steam in various forms had existed for a while; firstly in 2002 as a more efficient distribution engine for Counter Strike then to provide authentication and matchmaking for the HL1 multiplayer after Valve's publisher Sierra planned to turn off their servers in 2004. They offered upgrades for all old HL1 cdkeys to a steam account and then started selling their games (I think Counter Strike: Condition Zero was the first new release) through it too... which wasn't appreciated by Sierra: http://en.wikipedia.org/wiki/Valve_Corporation#Valve_vs_Vive...

[ZoFreX]

There was, and is, a lot of FUD about the HL2 leak. One of the confusing factors is that there were actually multiple leaks - at first it was "they just stole some code which no one can get to compile" and by the end it was "there are playable levels". Basically everything Valve had at the time was leaked it seemed - there was a huge amount of assets, a fairly complete engine, multiple levels including bits of the now-infamous E3 demonstration.

The reason it was delayed is, quite simply, that it was nowhere near ready, and I think this would have happened with or without the leak. Valve aren't exactly renowned for releasing on time, there's no way they would have released an unpolished game just for the sake of a deadline.

[frou_dh]

I had hours of fun with that leaked HL2 tech demo that was essentially a room with a pool of water and a bunch of physics objects to weld together and throw around. Heightened my desire to buy the finished game greatly.