As of release v4.3.3 audio capture is supported @ 8,16,32 and 44.1 KHz using AMR-WB (PCM) and AMR-NB codecs. Audio quality is best at 44.1 KHz and there is a noticeable drop in quality at other sampling rates.
The implications are that some applications (depending on its implementation) will not record very clear audio. Applications that leverage voice commands are not typically effected by this as they usually capture audio at the highest quality setting, which is 44.1 KHz in our case.
AAC encoding is not supported as its not supported by the Beagleboard BSP
Recording using the internal microphone appears to record a noticeable amount of noise as well