Is that really all Mass Effect is to you? 'Rules'? Not history, people, places? The fact that it felt like a living place?
No. Mass Effect is, to me, a wonderful set of games with a subpar ending at the end with a strong protagonist that I came to recognize as unique to me based on the playthrough I went through, a cast of wonderful characters I came to care about, and a galaxy I loved to explore.
But the rules of the mass effect universe does mean it's impossible to step away from those characters I have grown close to. This upcoming game is going to be set in the far future, so I know I won't be seeing Garrus, Tali or Shepard again, and there's nothing wrong with that. There'll be a new and improved Mako, which I approve of, I won't be on the Normandy, which just means I'll get to enjoy a new ship. There will be new characters that I will either grow to love or hate, and a new story for me to judge based on the quality of the writing and how well it works in the Mass Effect universe.
If Bioware wants to expand on the Mass Effect universe, I have no problem with that. New characters, a new protagonist, and new places to explore. What will make it a Mass Effect game or not is its ability to stay within the rules of the Mass Effect universe, with the mass effect drives and fields, use of dark energy in biotics, element zero.
This game will be an expansion of what's already there, and one that won't have to deal with the baggage except what we the gamers bring with us, much like KOTOR was an expansion of the Star Wars universe, even though we never met Yoda, a Skywalker, flew the Millennium Falcon or that stuff, but it explored the planets, kept to the rules set by Star Wars in how its universe works, and because it separated itself from the movies, it was open to a whole new level of potential content that Bioware and LucasArts could work with.
I'm not saying it's a good idea or a bad idea, but one I can see the logic behind after the fiasco of the ending of ME3, and I'm willing to wait for more information before I pass judgment on whether it'll work or not.