Is there a HOWTO for this somewhere? Sounds like a very useful setup
All the docs needed to set up that bit can be found on docs.redhat.com ... the identity management guide in the rhel6 section.
I've written some more advanced guides on the freeipa wiki (look at how tos under documentation) covering Apache auth against IPA and IPA for httpd certificate management... will soon add my kvm/libvirt/vnc authentication against IPA doc as well - just waiting on feedback before adding it to the how to section.
If there are any specific how tos you'd like to see on there feel free to suggest... and always feel free to ping me...