The Paparazzi team have released a new IMU board called Asprin. It's just the accelerometers, gyros and magnetometer sensors (no processor) and is available for $110 at Joby Robotics.
Strangely, I can't find any mention of it being open source. Is it actually possible that Paparazzi is no longer supporting open source hardware? That would be sad if true. They seem to have deleted the Hardware folder from their repository. [Correction: the hardware repository is here. It only has the schematic of Lisa (no board file) and no files at all for Asprin]. I've asked for clarification, but haven't heard back yet.
Remember that Paparazzi's tagline is "Bringing freedom to UAV since 2003". Maybe it should be "Bringing freedom to UAVs, 2003-2010" ;-)
[UPDATE: The official statement: "For the time being the Eagle files for Aspirin are not released in a OSHW definition compatible way. We at Joby Robotics would love to be able to release the files. But we don’t feel comfortable with that at the moment. It is a continuing discussion here at Joby Robotics, so let’s hope for the best!
P.S. Aspirin is not a “Paparazzi” design as such, it was developed at Joby Robotics with close collaboration with Paparazzi community. It may have not been reflected by the article properly for some readers."]