0.6 is barely out a day and I've just merged tons of awesome into 0.7!
(A)
Tim Bielawa has provided a nice patch that will make the occasional YAML error an amazing experience that highlights approximately where an error went wrong. This code came over from taboot, which was a tool/language on top of Func that was one of many major inspiration points for Ansible. Generate a YAML error (I suggest leaving out a colon) and you'll see improvements.
(B)
Matt Wright has provided a ton of new modules -- all simple -- no docs just yet, but you should be able to read the source and figure them out. pip, easy_install, supervisorctl, and apt_repository. They do what you might think they would do.
I am very impressed about how simple these are, and I hope they encourage more people to write modules. I was not going to include things like pip in core before, but it's super evident that despite supporting modules in any language, we have a ton of hardcore Python folks here deploying web apps, who really wanted this stuff. So, it's in core!
I'm open to expanding core further where things are going to be reasonably widely used and easy to maintain.
--Michael