I already use it for some little new projects. I'm sure a lot of legacy stuff won't be able to move on to the new standard for a while because they need backwards compatibility with old compilers though.
I'm itching to start using this stuff in QuickBooks; I love smart pointers but hate auto_ptr and being able to safely use STL containers with smart pointers opens a new world of entity processing.
The apache table[+] has been updated as of this month, and MSVC (with a version given as "11.0 nov'12") now is looking rather better, but is still missing constexpr... :(
Still, it appears that there should be fairly good support in all major compilers within the next few years, at least if you can depend on your devs using relatively up-to-date compiler releases (not at all a given where I work!)... :]