I loved it. It was fun, funny, had original aliens, and an overall sense of mystery. Basically it was something we hadn't seen in a few years, even better than most of RTD's good episodes.
Smith did a good job, I can see him being quite good in the role. There was a certain mixture of both Bakers that really worked. I can tell he's a smart actor who put thought into the role before really tackling it. I also liked his style and and the Tardis redesign. It all has a nice retro look which adds to the sense of fun.
Amy also has a lot of promise. It reminded me of Renette from Girl in the Fireplace with a happier ending. It shows that he's willing to be creative with the time travel aspects (I especially like the added 2 years at the end). I like the twist that he's her imaginary friend who she drew and obsessed over since childhood. It's so much more than the Rose/Martha crush because her infatuation with the Doctor goes back before she even thought of sex, running out on her wedding was a brilliant touch. She's also fun and tough without being "feminist tough" like the RTD companions. And she's hot.
I think the days of Doctor-praise and heavy melodrama are finally over. The show is no longer about Rose, the Time War (which I still feel cheated we didn't get the rumored Mcgann episode), or the Daleks/Master as the season's big bad.
I'm happy....though the jury is still out on the theme song, I was hoping for one closer to the Hartnell-Baker eras.

Bow ties are coool.