See http://www.gnu.org/software/libidn/, apparently a prerequisite for #117706.
Gah, that patch that gets the encoding within jwhois just looks *wrong*. Aside from that, interesting. I'd be curious to see the libc authors opinions on integrating that into libc for getaddrinfo()
IDN support is integrated (using Simon Josefsson's GNU libidn) to glibc 2.3.3 - FC2/3 already have working IDN support (tested). The package "libidn" is in Fedora Development also available. Bill, I know that this encoding hack is just wrong, it's removed now and the patch is updated, because DENIC allows querying for ace domains also, yet :-)
Closing as fixed in rawhide.