From what I could discern from the anime and manga, was that Ichigo's hollow powers and soul reaper powers were one and the same. Remember Hollow Ichigo being a part of Zangetsu? Putting all the rest of the history aside, when Ichigo learns the Final Getsuga Tenshou, he does this when Hollow Ichigo and Tensa Zangetsu combine, that is in essence his power is whole when he fights Aizen, so we could say he was fighting with his Hollow powers without using his mask... So yeah, I think his Hollow Powers are there, we'll just have to wait and see what form it will take. Personally, I would love to see him put on the mask of his horned hollow form. Maybe he doesn't need to now.... This is my opinion, please don't hate if it sounds far fetched or lame. >_<