Yes, I think you are right, I am having a lot of trouble getting any participation. I am now working on the AI enemies. I think that like most games, playing a single player campaign or skirmish against the AI will be fun, but online multiplayer will be better. It will be interesting to see whether adding the single player option leads to more multiplayer participation as you suggest.
There were several important reasons why I did multiplayer support first.
(1) In terms of software architecture it is much easier to add single player support to a multiplayer game than vice versa.
(2) Once you have written the AI, it is hard to change the mechanics as you will break the AI. However, once you have settled on the mechanics, it is easy to change the AI. Therefore you want to establish the game mechanics first. It is easy to get the game mechanics wrong and imho getting them right is the most important aspect of any game. So I was hoping for a good chunk of multiplayer participation in order to test that the mechanics are balanced and produce addictive gameplay.
josh