It wasn't made to be exciting. For exiting go look elsewhere.
It was made for some very pragmatic goals:
1) to be used in the same context as Javascript (web clients mostly but some server too) 2) Look familiar to JS programmers 3) be more like Java and remove the bizarro JS behavior 4) be able to be made faster than V8 5) add some handy stuff to the mix.
Exciting does not come into play at all, and with this goals it should not.
With "exciting" you get Haskell or Clojure, languages with such small following that they celebrate it with blog posts when they are used by some company (personally, I like both, and they are both better than Dart for tons of things but not for Dart's specific goals).
Not that Dart is used by anyone as of now, but one of their goals is to have it be used. And conventional beats "exciting" every time in this goal (All the major used languages: C, C++, Java, JS, Python, Ruby, Perl, C#, all fairly similar and conventional).