|laziness, impatience, and hubris|
In the case of C++11, the major compilers already support most of it. g++ is lacking on its regular expression support, and MSVC++ was a little slow with variadic templates, but I think they're implemented now. Most of what is most important is there; move semantics, rvalue references, ranged loops, auto and decltype, modified return value function syntax, reference counted pointers, lambdas, and so on.
But your second point is right on the mark; though everyone's excited to use these new features, often the new features are avoided in the name of backward compatibility, and I haven't a good feel for C++11 features being accepted into newer projects.
I can say that the standard library has been rewritten in most major implementations to take advantage of move semantics, which is a really big win that nobody really sees -- like trie optimization in Perl's regexes, it's just there behind the scenes.
Anyway.... I've taken us way off topic. I apologize for rambling in your thread. :)
In reply to Re^7: Real life uses for closures. (update: disambiguation)