User blog comment:Hunter Zealot/Mass Effect 3/@comment-3061137-20101212091135/@comment-2235714-20101212093725

Or it may be along the Mass Effect 2 plot vein. Actually, it's more accurate to say Dragon Age plot vein. The Reapers have attacked Earth. To defeat them and repel the invasion, Shepard must call on the aid of the other races and assemble an army to defeat them, assuming a joint armada could defeat them at all. Ride to Earth heroically. Epic battle. Exciting conclusion. Drinks all around. I'm not endorsing this option, just saying it is a possibility.

And technically speaking (spoiler alert), Shepard did die at the start of Mass Effect 2. Cerberus just had a Plan B.