Yeah dude to tell you the truth I don't think there will be much if any of this in this game.  I think there will be a singleplayer that will have some of these kinds of elements but will be mostly based on the core gameplay.  Demigod as far as I have known isn't based on times spent playing but rather on skill.  You can't just get gear in demigod by playing it for a long time.  There are insentives to play in the form of favor items that can be bought ith favor points earned through matches but I think mostly demigod is going to be focused on a fast paced multiplayer game.  I like this kind of gameplay too but when it comes to demigod I think the main focus will be pvp.

I am sure co-op missions like Tower defense or maybe even some RPGish maps (comparable to those in starcraft or warcraft III) will be made by modders.

Yea, like Mooglepies said, I can see this happening as a mod and it sounds like it could be made into something quite fun.

But the developers wouldnt really add a feature like that as they are clearly concentrating on the multiplayer aspect of the game and they've already giving us a singleplayer mode.

I'm under the impression that there is going to be a single-player campaign.  I do hope it is co-op accessable (everybody one 1 side)

Tower defense missions are almost a must, even with multiple sides.

In Starcraft and Warcraft 3, I loved the missions where you went "commando" and conducted the mission as an individual or small team. It was a great change of pace and fun to micro a couple of guys. I could easily see that with Demigod, so even if it doesn't show up in the official release, I hope that there's a large enough community to develop something like that for Demigod.

Yeah moogle, I remember back a while ago I made a post about longetivity and they pretty much crapped on that idea.  Orlean was talking about something to make maps with a "maya" but some other guy said that program is like a thousand dollars and extremely complex.  I don't know I mean you would hope they would put the extra effort in but to be honest it isn't really to their advantage because they want you to buy their next game too.