For RHEL 6.0 we delivered an old, very safe version of libguestfs (1.2). Even before RHEL 6.0 was out, we knew we wanted to radically update libguestfs because we had many major new features, and we had improved the speed of libguestfs by 4 or 5 times. Thus the RHEL 6.0 → 6.1 rebase was substantial.
For RHEL 6.2 we are not planning any big changes, but nevertheless we are going to pull in over 100 upstream patches and fix dozens of bugs.
RHEL 6.2 libguestfs will have the same official version 1.7.17
but in reality it will be very similar to the upstream stable branch version 1.8.11, the package which has been getting a lot of testing and feedback in Fedora 14.
If you are using libguestfs in RHEL 6.1 now and you want try out libguestfs as it will look in RHEL 6.2, have a look at these preview packages:
http://people.redhat.com/~rjones/libguestfs-RHEL-6.2-preview/
Richard WM Jones 