Well, we yet have to decide on implementation details. The requirement specs are along HiFi parameters, which means at level of CD sampling rate and format and S/N. This might not apply for mic input on same interface, which needs a preamp/boost that may introduce some higher noise floor compared to line-in level.
Simply go by the purpuse why we got this: it shall turn the device into a viable replacement for audio stereo recorders designed for high quality stereo recording of live events. Yet to evaluate if we can integrate high quality stereo microphones or we will just not bother to come up with stereo mic embedded and rely to plug-in mics.
/j