Based on the polls and the assumption our opinions matter, It appears.
1)There will be a way for the mass relays to not be destroyed (sending out the crucibles power through the relays without destroying them) 2)The conversation with the Catalyst will play out with some investigative additions and Shepard will have the ability to oppose the catalyst. 3)This one is less likely but either Citadel destroys all reapers, Citadel destroys reapers at earth and over time the rest go bye bye or fleets have to do all the work (personally i say just destroy all reapers and keep relays intact) 4)It is likely fans will have the option to bypass the catalyst scene. As an indoctrination theorist, I say keep the scene and pick up from where it left off 5)Shepard should reunite with his/her crew. 6)Shepard talks to harbinger one last time, then the rest of the forces focus on harbinger while shepard and anderson go to activate the crucible, and confront the illusive man 7)Indoctrination Theory to be confirmed (from after the harbinger beam to the end of the catalyst...all a dream) 8)A super happy ending as well as an ending with heavy losses. In either case, Shepard reunites with crew. 9)Most dont care whether the stargazer stays or goes. I agree 10)Epilogue shows how all the races get along (or dont) after the war 11)Shepard and love interest have moments 12)Shepard and squad have moments
Ok based on this, current catalyst ending stays with the exceptions that shepard can question and/or go against the catalyst. In the end, Shepard makes a choice but on his/her terms perhaps. Indoctrination theory wins so Shepard wakes up after the whole ending scene and realizes it was a dream. Anderson wakes up nearby too. Harbinger speaks to both of them one last time before Shepard's reinforcements arrive to take on harbinger. Anderson suggests they make a run for the beam while Harbinger is distracted. While moving through the Citadel, Illusive Man shows up and you get to fight him (in the form shown in The Final Hours of Mass Effect 3.) While youre fighting him itll cut to Harbinger at a few points (reminiscent of the fight with Saren) Once you kill the Illusive man, Joker flies in and depending on Normandy uprgrades either delivers the final blow with the thanix cannon, or has his ass saved by someone else and they take out harbinger. At this point shepard will activate the crucible and it will fire. This following idea is debatable so thoughts would be good. If Shepard chose control in the dream, Shepard will turn and start talking about how humanity comes first and Anderson will have to kill Shepard. If Shepard chose Synthesis in the dream, Shepard will turn and talk about how we should work with the reapers to reach the highest level of evolution. Regardless, Anderson will have to kill him and fire the Crucible. If shepard chose destroy in the dream, shepard will not fall under indoctrination and activate the crucible him/herself
Afterwards, depending on EMS and such, either the mega happy ending occurs or a heavy losses ending occurs with or without Shepard present. There will be some location Shepard will be in and he will be able to talk to all normandy crew as well as characters from the first two games that made it this far (i.e. miranda, wrex, tali etc.) In addition, a moment with the love interest will occur. If Shepard's not present, love interest and crew will be seen reminiscing about Shepard and how its a shame he/she had to die etc. To trigger the epilogue, Shepard goes to talk to Anderson and Hackett and after a final convo, there will be a Dragon Age Origins style epilogue illustrating the fate of all the races.If Sheps dead, it will automatically go to Anderson and Hackett talking after the reminiscing. Who got granted embassies, who started wars and took names etc will be in the DAO style epilogue. In addition, it tells you what each character and shepards love interest went on to do.
It's not perfect but I think it's pretty damn good.