Although I'm 100% .NET, C++ is still my favorite programming language. You have to take care of cleaning up your own mess, no garbage collector to rescue your application from memory leaks.
A while ago, I had a memory leak in a .NET application that makes extensive use of the StringBuilder class. A large StringBuilder object was occupying Generation 2 memory. This object was never cleaned up by the garbage collector. At that moment, I wished that the garbage collector wasn't screwing up my day and that I could free the damn memory myself. The new C++ standard adresses this issue:
A C++0x compiler must provide garbage collection, which the programmer can use on request; "don't GC this region of code" is still the default. This "opt-in" model leaves existing programs' semantics unchanged, while providing real GC support for programs that want it.
I'm also glad that the new standard specifies the need for concurrency libraries. I'm really looking forward to this.
You can download the first partial draft of C++0x here.