DEFCON released today

VVrath writes: Independent developers (and bedroom programmers), Introversion are releasing their third game, DEFCON at 6pm GMT today. As the successor to the sleeper hit Uplink and the IGF award winning Darwinia, this is one of the most eagerly awaited indy games of this year. Based on the game of thermonuclear war played in the film WarGames, DEFCON gives you the opportunity to nuke the hell out of your friends (and enemies), with the player who loses the least crowned victorious. With this being Introversion's first game for sale by download only (it's available on Steam as well as through their own website), does this mark the end of indy games being sold in shops?