It’s been more than a year since I wrote something about Qt. This is mainly because I retired myself from the team and focused on other teams that needed urgent attention. However, lately I had some spare time to contribute to Qt again and update 4.9999 ebuilds to a working state. Furthermore, I pushed some initial ebuilds for Qt-4.8.0_beta1 and Qt-4.8.9999. Both sets are merged successfully on my testing boxes so they should by ready for you to test them. Qt-creator-2.3.0_rc is located in qting-edge overlay as well, but because it requires >=Qt-4.7.4 it makes no sense to commit it to portage. So if you want to use it, then you have to use >=Qt-4.7.9999 ebuilds :)
If you have any problems, please use forums to report them or open a bug on https://bugs.gentoo.org.