I think the industry is shifting towards a more inclusive 'everyone gets to play' kind of style. You can see this now with the spearhead that is WOW making all their content available to everyone whether you're in an organized guild or a solo player (LFD/LFR). You see that here with the story mode/group finder versions of multiplayer content too. It seems to me those kinds of options are designed for the single/solo player type, not the social butterfly that's already in a guild scheduling events to do with them.
Companies know that single/solo players actually make up the bulk of their members, so it's all about making multiplayer content attractive to them now. The days of MMOs being multiplayer exclusive (EQ, DAOC, etc) are long gone. That's not to say companies shouldn't still add in content for those types, but understand anything they put in is going to have to be playable by the soloist too. It's no wonder SWTOR is focusing mostly on the solo only stuff, given this.