A new release of khal is here: khal v0.2.0 (also available on pypi).
If you want to update your installation from pypi, you can run sudo pip install --upgrade khal.
From now on khal relies on vdirsyncer for CalDAV sync. While this makes khal a bit more complicated to setup, vdirsyncer is much better tested than khal and also the bus factor increased (at least for parts of the project).
You might want to head over to the tutorial on how to setup vdirsyncer. Afterwards you will need to re-setup your khal configuration (copy the new example config file), also you will need to delete your old (local) database, so please make sure you did sync everything.
Also khal's command line syntax changed qutie a bit, so you might want to head over the documentation.