When did things switch from using the avi files to mve? When I originally downloaded the game, all you could (I thought) were the avi's? I got it off HOTU
An in-game MVE player was added a while back. 3.6.9 has a new Theora movie player too, which works far better than the AVI support, and is cross-platform. The original MVE movies are going to be converted to Theora as well, since it allows for a considerably smaller file size. As the file size of the MVEs has largely been the excuse for people to continue to use the AVIs, having Theora support will easily remedy that.
Post-3.6.9 builds will have all AVI support removed, so it won't even be an option in another month. The 3.6.9 release (which should be this weekend) will be the last with AVI support. The only options will then be MVE or Theora.