BioWare has said the next Mass Effect is in "early development," which is kinda vague but hey, we just saw the end of the Trilogy this year.
The developer has been turning to the fans for feedback and suggestions concerning the new project, which is always good. Most recently, Mass Effect executive producer Casey Hudson posed the following query on Twitter :
"Parsing through your thoughts on the next #ME game. Would you be more interested in a game that takes place before the trilogy, or after?"
So would you rather have a prequel or a sequel? For those who completed Mass Effect 3 , they know how it ends…and how challenging a sequel might be. Then again, it can be argued that prequels are a little overdone and even cliched, despite the fact that BioWare usually has some of the industry's very best writers at their disposal. At this rate, there's no guarantee the new ME will be called "Mass Effect 4" as that'd be a pretty silly title for a prequel.
It's nice to know nothing is set in stone, and the developer is open to all sorts of suggestions. So feel free to make your voice heard.