C++11 (formerly also known as "C++0x") is the current standard for C++, adopted in August 2011. Many parts of it are available in GnuCpp version 4.3.0 (or later), by Microsoft Visual C++, by Intel's ICC, and by many other compilers.
The FAQ has a pointer to a table of which compilers support which new features.
C++11 features include support for anonymous functions (lambdas), concurrency, efficient "moving" of objects (via "rvalue references"), VariadicTemplates, extensive new library facilities, fairly strong C99 compatibility and more.
For later developments in CeePlusPlus standards see CeePlusPlusOneWhy.
'C++0X' looks a little like a dead fish.