I think he got a lot of mileage out of the absolute perfect storm that was The Dark Knight.
Rises is probably as good as Begins. Nolan had neat idea and ran with it. I'd say they're the best Batman movies to ever bless the big screen. :|
EDIT: I also think Nolan's Batman was better than anything Frank Miller ever did with the character.
Miller was... OK. But the main reason he's gotten so much 'praise' is because it was around the time of the Watchmen and that period of the 80s, it was the start of 'The Iron Age' of comics, not to mention that 'deconstruction' was the order of the day.
However, one of the key elements that most of the Batman movies always miss out to date, is the detective part of Batman.
And before you say that wouldn't work, I'd like to point out that the first (recent) Sherlock Holmes film captured that perfectly.
So I stand by my statement. Nolan's Batman isn't all that good because he still missed the integral part of the Bat. His mind. And in the later films he even took away his body.