It appears that multiplayer will be in the next Mass Effect game (not called Mass Effect 4, apparently), as BioWare is seeking an "excellent Producer" to help craft that title's online experience, whatever it may be. The smart money is on it being something akin to Mass Effect 3's popular and mostly well-received co-op mode.
"Things are getting real now and I need an excellent Producer to come shape online for the next Mass Effect", tweeted Mass Effect Senior Development Director Chris Wynn, with a link directing prospective applicants to BioWare's careers page.
Could we see a return to Mass Effect 3's multiplayer and will it tie-in in some way with the game's story, providing additional 'Galactic Readiness' for the end game? It's entirely possible, but until BioWare confirms something more concrete, we'll just have to wait and see.
Source - X360A