mongodb 2.2.0 is in epel-testing for EPEL 6.
Due to concerns about updating from 2.0.x to 2.2.x these will probably
remain in testing until 2.2.1 is out and packaged.
So, if you are running EPEL 6, you can test mongodb 2.2 by using the
testing repositories. But it won't go into those main repo's until at
least mongo 2.2.1.
I'm pushing ZNC 1.0-alpha1 to stable. I've been using it on my server for
a while now, and it's been working fine. It's a fairly big update, but is
not supposed to require any manual configuration changes, per the
developers, but you might want to check after updating to make sure
everything is ok.