I've only played ME1 so I'll be careful not to read ME2 spoilers in this thread, but one thing I loved about that game was that it was made or written by scientifically literate people who actually know a thing or two about astronomy. That was very refreshing. The portrayal of celestial objects was quite accurate and I liked reading the planet descriptions. They certainly didn't dumb the game down in that department. It actually kindled my interest in astronomy. The space exploration was great and really swallowed me in. It was fun to move from galaxy to galaxy and discover the systems there. I imagine that once we have the technology to travel beyond our Solar System, landing on a foreign planet might look similar to the view you see in ME.
I wished there were more interesting side quests though, they were all pretty much the same on most planets. But if ME2 and ME3 are as good as ME1, they're a buy for me.
Good trailer, and of course they'll add space exploration, duh!

They'd be crazy not to add that.