The OBi is clearly marketed as an international product. It makes a lot of sense for the OBi to give instructions in the AA in other languages. If the OBi needs voice files to have certain specs, that can easily be arranged by the sys admin of the OBi device. A recording tool can be offered up by OBihai, similar to your offering of the syslog tool. I'm not certain how difficult it would be for OBihai to allow users to upload voice recordings. I think you would need to be able to keep the original AA voice somehow. Perhaps during firmware upgrades you can have an option to keep modified recordings or setup default AA recordings.
I'm certain if you took a poll of the OBi customers using the unit in an international setting, this might be the number one request. The AA serves as the front end for the international callers. Once the caller can understand the OBi instructions, all the other OBi settings are pre configured and don't require any user input other than dialing a speed dial or dialing another tel #. It would be interesting to know what others think about having this ability.
This would be another small step in the internationalization of the OBi product.