Actually it does matter. It is just not always the right moment to optimize your code. There are several patterns applied properly at the start of most project helping you worrying about performance at a later stage. Obviously this won’t help if you need to do highly CPU demanding processing (neuronal network, nuclear bomb simulation, …).
C++0x is the standard which describe the new C++ language specification. It’s still draft. The main focus of the C++ committee is the development of the core libraries. In the language itself, the committee will introduce lambda functions (like Clojure, scala, groovy, ruby, php, …), nullptr variable (interpreted as a pointer whereas today NULL is a defined integer most of the times, it depends on the compiler) and few other minor changes.
Both Visual Studio 2010 and gcc brings support C++0x with their latest versions. I’m very curious myself to test lambda functions. For those of you who want to try them, you will find here the 2 tables describing which features each of the compiler comply with.
Visual Studio 2010 : http://blogs.msdn.com/vcblog/archive/2010/04/06/c-0x-core-language-features-in-vc10-the-table.aspx
Gcc 4.5 : http://gcc.gnu.org/gcc-4.5/cxx0x_status.html
It’s obviously too early to use it for production development, but worth spend some times to test these new “features”.