We've released APM 2.22, which has a bunch of bug fixes and improvements. MAVLink startup is now much faster and will work even if the hardware fails the calibration test. A bug in the driver for the new 5883 magnetometer is fixed. Various (mostly minor) navigation bugs fixed. MAVLink comms are also improved.
It's now available for download via the Mission Planner. Remember to go through the setup process again after loading (always a good idea after loading new code).
For those who need the source code, it's here. The next version of the code, 2.23, will have full camera control (both autonomous stabilization and point-of-interest following and a full suite of MAVLink commands) implemented.
Meanwhile, the Mission Planner continues to improve in leaps and bounds, thanks to the tireless work of Michael Oborne (subject of the next Meet the Developers post). New features that have been introduced in recent versions include: