Mass Effect 3 multiplayer could return in Mass Effect Legendary Edition, BioWare’s Mac Walters has revealed.
~Mac Walters at BioWare.
Mass Effect 3 Legendary Edition has been amended as a result of its current lack of multiplayer; the mode used to bolster the single-player Galactic Readiness...
I want to say it's one to one, but in all honesty I'm a bit fuzzy there. I can recommend JoyFreak's sister site AdminIntel - Admin & Webmaster Resource where there are lots for people of varying degrees of expertise with development, you likely can get a far more precise answer there!