Answer: A Lot!
If he'd only given us Captain Jack, the real, original omni-sexual one (as opposed to the imposter who shows up on Torchwood from time to time) it would be enough. If he'd only scared the shit of me in Blink and given me a life-long fear of statues, he'd still be a genius. But with these two episodes, he moves into some other pantheon of awesomeness.
I have no problem with whatever relationship the Doctor and River Song may have in the future, because I'm not totally down with that asexual Time Lord thing. (Full disclosure, I don't have a lot of familiarity with the character prior to New Who.)
Mostly I love this man because he manages to surprise me. I had NO FUCKING IDEA what was going on, especially in the 2nd episode and I totally loved that. Because the thing I hate most in the world is watching a movie or tv show and knowing EXACTLY what's going to happen.
Plus he somehow manages to comes through with happy endings when you think it's impossible for that to happen.
Kudos also to Euros Lyn because I think this is some of the best acting I've seen from David Tennant and Catherine Tate in the whole series.
The episode confused me, scared me and made me incredibly happy.
Now just give me some Captain Jack (hopefully the real one) and my Who-series will end sublimely.