Just finished my first playthrough of the game, saw all three endings. Can't say they really explained a heck of a lot. The endings were all very similar, a couple of minor color changes and then the stargazer dude. That better be leading to something otherwise, it does feel like a waste of time to play.
With the indoct-o-ending, it would have been good if it showed my Shepard at the helm of a Reaper to be the controller of the things and the romance option going along for the ride. But just to see shepard desolve and cookie cutter endings, not so satisfying. I can live with it, but I will think twice when the next Bioware game comes out... Something I doubted I'd ever say after ME:2's Lair of the Shadowbroker DLC.