So I've played for about 3hrs so far and absolutely love it. Can instantly tell I'm going to play the hell out of this game. It seems they took all the good parts of the first 2 games, and cranked them up a notch to make them awesome in the finale.
I really wish there was a way to tweak your backstory though... I lost my old savegames (my xbox was stolen when our house was broken into). I didn't think it would be an issue as far as the main plotline stuff goes... who lived/died/etc... but I'm definitely feeling like I'm missing out on some interaction with Liara, as she was my shep's love interest through both ME1&2. Plus I did the Lair of the Shadow Broker DLC, so...
Oh well, I suppose if I really want to be OCD about it I could just re-play ME1 & 2... but I sank a couple hundred hours into those the first times around... don't think the Mrs. would allow me to do that again. I'll get by.