OK, so Mass Effect 3 is set to be announced at the Spike VGAs (seriously, is this the only place that games can have an awards show? Can't we have something at least a little bit classy?), and it's probably going to have multiplayer. Outside of the fact that no game has ever needed multiplayer less than Mass Effect does (and I feel confident in saying that, having played literally an hour of any Mass Effect game), I think it's pretty clear to me where this direction came from.
BioWare is owned by EA. And EA thinks that single-player gaming is "dead." Outside of how ludicrous that statement is (though I'm hardly representative of the gaming community at large, I haven't played a multiplayer game since I first got Mario Kart Wii) from an aesthetic standpoint, even from an economical standpoint, it's super silly. There are only a few games that people actually play online with any regularity, and drowning the market in more shitty multiplayer games with no narrative context is not the way to move this medium forward.
Anyways, we'll update you if this indeed turns out to be true, and you can bet that when I get my copy of Mass Effect 3 (theoretically), I won't be trying out the multiplayer.