Well think about it this way depending on how he gets his powers back tis can mean a few different things.
The First thing which comes to mind is that if it ends up becoming a reasonably easy procedure to regain his power then he an use the final getsuga over and over which allows him to perfect fighting in that form. Also this should bring back his hollow as they were technically one in the same as I saw it. So, Final Getsuga+ Full Hollow = ?.
Or if it is not a more or less permanent patch or one which can be done over and over he still would get his hollow for back for the same reason as above and we don't know how far he can go as a full hollow and he has yet to learn how to control it which would be something for him to learn and expand his powers from that base.
Finally one last thing which I considered as a possible out come is similar the my second option but is more based on the people in xcution. Each of them is similar to Chad, Ishida and Orhime, and Ishida said himself he has felt like there is riatsu but something different surrounding Ichigo so he may learn a new power similar to theirs or as Ishida's father said it was like nothing he had seen before so it is possible that though similar it could be an entirely new thing kind of like the divide of Hollow/Shinigami/Quincy so add one more gives you Hollow/Shinigami/Quincy/?.
One other less interesting way which Ichigo can expand his powers would be though Kido but I highly doubt that will happen considering how he smashed a 90th "level" technique by brute strength which Aizen was Jizzing himself over performing perfectly
Also rule 1 from playing DnD no mater how stong you are there will always be something stronger than you out there.
One thing I do want to know is if his father is related in this. Since he himself, though he claims not to know how, reclaimed his powers after using the final getsuga or at least thats what I feel the story has alluded to. Also I do know that whats his face the big guy that made contact with Ichigo said bringing up his father was nothing more than bate.