I had some trouble switching to the new profile 17.1.
Following the advice in the news item didn't suffice.
I had to reinstall some packages "by hand", e.g.
I had to reinstall util-linux quite early.
I had to reinstall x11-libs/libva without the opengl USE flag, since it
couldn't find libopenGL otherwise.
After reinstalling mesa (which depends on libva), I'll try to reinstall
x11-libs/libva with the opengl USE flag.
Currently I'm reemerging gcc bintuils glibc before I proceed with the
other packages selected by
emerge -v1 /usr/lib/gcc /lib32 /usr/lib32
Perhaps, it's only me.
Helmut