
Having just replayed ME1 (lost my hard drive, couldn't bring myself to play a prefab Shephard in ME3), we actually know quite a bit more about the Reapers' methods and why we sorta have a chance than you guys are recalling.
The normal method is to bring in the Reaper fleet through the Citadel and then shut down the entire mass relay network. At that point, the entirety of galactic civilization that has grown around that network is crippled and each system is cut off from the others, preventing any coordinated defense. The Reapers then spend decades if not centuries idling from system to system wiping out pockets of civilization at their leisure. They missed a spot in the form of a handful of Prothean scientists in stasis, who took a one-way trip to the Citadel after they left and programmed the Keepers to disrupt the Reapers ability to warp in. Hence Sovereign needing Saren to retake the Citadel and get the plan back on track.
But Shephard weren't having none of that, so we're facing a Reaper invasion with a functional galactic civilization whereas the Protheans and all their predecessors had just been plunged back into the Dark Ages when they were attacked. Not that Lauren's point about Lovecraftian villains doesn't stand, but it's not just Shephard being the ultimate badass that gives us a chance. In fact, no matter how things shake out, most of the credit for defeating the Reapers should go to the Protheans.
Point taken. I was a bit hazy on the details. Still what I said still stands. Seeing the power that Sovereign had and multiplying that by hundreds if not thousands means the Reapers would have to be de-powered in order for Earth to hold out for minutes, much less for enough time for Shepard to do whatever it is he has to do.
Anyway, we'll know soon enough.







