We have modeled the emissivity and throughput of the new AO system and IR camera to be installed on the Shane 3-meter telescope at Lick Observatory. The model's predictions fare well when compared with those of the Keck AO system model and the measured background and magnitude limits of the existing AO system and detector on the Shane telescope. We conservatively predict that the new system will be able to study fainter objects and reach target SNRs 10-13 times faster than the current system. The model's predictions are predicated on worst-case summertime temperatures, dusty optics (3% dust fraction) and degraded coatings. On a night with median temperature and seeing, if the optics are kept clean and the primary mirror is re-coated (2014), we expect the telescope to perform better than predicted. In addition, we have not yet factored in the longer exposures that should be possible with the stability and tracking improvements afforded by the new instrument assembly. We are confident that the ShaneAO system will enable the 3-meter telescope to continue to operate at the frontier of Astronomy as it has done for more than 50 years.