Is Multiplayer the future?
I think it's a great part of the future.
I came to Total War because I wanted strategy and tactics. I've always been a strategy gamer and actually bought Shogun because I knew the board game Shogun where you also had to conquer Japan on a province map. It's very similar.
At that time, my only MP experience was connected to 1on1 Console games, Lan-compatible games like UT or AoE and the like. When I started playing Shogun I couldn't play the 3D part because of my machines specs. It took a while until I could play this part of the game and it really became something new. But I didn't play MP until Medieval came out. It had again to do with my machine. When it was finally capable of running a 4vs4 custom I logged in to Shogun MP. This may sound silly but the atmosphere of Shogun, its whole Samurai-theme made it more attractive to me. Once logged in on a Monday evening I met people like ShinGaijin, Mimesaka, Kansuke and a lot of others who gave me the feeling to be really welcome, although I was a really bad player at that moment. But it gave me confidence to try Medieval MP, too. Well I have mixed feelings about Medieval, the Lobby was crowded with idiots, insulting each other and spamming the lobby into unreadability. I did some nice games, won some lost some but it didn't really catch me. The limited number of different armies and the almost impossibility to win with Turkish forces put an end to it. I returned to play some Nap Mod games, which was fun, but again not that good. It's also a question of time. I would often join the lobby to find a decent game and had to wait for an hour for the game while people dropped out of it, didn't join, took ages to build armies etc. In that time I could've played a few campaign battles.
BUT, after a while it's just no real challenge anymore. Well sometimes the AI could surprise you, but most of the time you would rule the field. So, the real challenge lies in MP and people want to be challenged. It's no fun if you can't loose and the ultimate fun is to compete against another human that you know nothing about except his nickname. You don't know what to expect.

The point I want to make is, that the SP part has to function properly and provide a challenging AI with tactical brains. All you really need for the MP part is a set of balanced playing pieces/ i.e. units. Like in chess. I may agree that it is up to the players community to develop the best settings for a balanced play but the rudimentary engine should provide the best start possible.
If you look at the development of computer games you can see that when computers started to communicate they started to play against each other. This development led to the idea of world-wide competition and rankings. Some console games do a very good job in this respect and I dare to say that any game that wants to be a classic has to be part of this development. Rome needs a good MP part to compete with other games. Even if the SP part would be perfect there would be the urgent wish to compete against other human players.

R'as