Really since KC went down in March; he traveled to Milwaukee for the NCAAs. Don't know if the three additions this summer caused them some rethinking for a while on Ellis.
By this summer it has become fairly clear that Halford was the only PG alternative to KC and that was too thin.
The addition of Ellis does a number of helpful things immediately. Most importantly, it takes any notion away from Bartley, Fischer, and Winder that they may be asked to play out of position at PG. They tried Winder there as a freshman and soph and it didn't work out for him or the team. Bartley was tried this summer and Fischer was in the discussion. That is history. It's KC, Halford, and Ellis, period. Some positions are easily fungible for good players, but PG is different. Trying to force that messes with the heads of everyone on the team.
Bartley can now work on getting his minutes at SG and SF. Winder and Fischer have all doubt removed as to their roles.
Edit 9/15/14: i now think some of this analysis is not correct in that Ellis was brought aboard by the coaches as a deep bench player. They continue to look elsewhere for backup to KC at PG.