It could potentially be interesting if Aleph One were able to checksum the texture set, sounds, custom weapons, etc. currently being used for a given network map, and send anything that doesn't match what the user on the other end is using. This would allow people to gather games using maps from M1A1, Marathon 2, Marathon Infinity, or any number of third-party scenarios without having to coordinate with the other players to make sure everyone is running with the same game files selected. This may have been bandwidth-prohibitive in the past, but with the proliferation of high-speed Internet in this day and age, it could be feasible as long as the game had some way of telling what textures, sounds, etc. were being used for a particular map and to send only those particular items.
Unfortunately, it isn't possible to tell which shapes, textures, and sounds will be used just by looking at the map. I have a pretty good upload bandwidth of 5 Mbps, and it would still take almost 2 minutes to send 25 MB worth of data to 7 players. When you consider that regular budget DSL would take 20x as long to upload, and some scenarios are as big as 400 MB, this is still very impractical.