Question

so C++11 is out... is it prudent to toggle the C++0x option in GCC?

Answer 1

It couldn't hurt to turn it on, read the spec and try a few things :P
Don't expect all your code to compile on MSVC just yet. It only supports lambda functions, auto keyword, static_assert and rvalue references out of the spec at the moment - however, those are the most important things in C++0x ;)

Answer 2

It also depends on what you are writing the code for. Some of the newer features of the languages may not port to other platforms. All compilers do not support all the features of these newer standards. But if you are not worried about moving your code to other platforms, then you could turn it on to sample or use the newer features.