DotA 6.72c 6v6 Map just came out. As title says, this is a modified version of original DotA which supports slot for extra two players instead of regular 5v5 game. However, it voids the referee/observer slot and makes the game more challenging and gank oriented. The only downside is that it makes the game more lengthy and time consuming.
DotA 6.72c 6v6 Map Download:
http://www.mediafire.com/?zteq7za4dv67w83