personally, something like virus mode from timesplitters would be better.
but what I think should be in the next one (other than my many other suggestions), I think you should be able to use whatever character wads you want in multiplayer mode (ie each player loads their character wads individually) but the host can choose to prohibit certain wads from that game (i.e. HMS11-something) and can save a preference list for the games he/she hosts. and the admin should be able to ban wad's in the middle of the game.
This way, people can use their own custom wads (i.e. mardic, srb2 playa, etc) and not have to hope everyone else that wants to play has it.