I'm another who is along the same lines as Quincy in that we should have replaced Arteta (and Edu) last summer, but with things as they are atm I am prepared to see how this season and the summer transfer window plays out.
That said my reasons for wanting to replace him are probably different to most and in principle they still remain the same as I have already said previously.
I also think we have reached a point regarding the style of play that we are now starting to see how it will fit together, and any potential replacement would need to be able to use this as a baseline moving forward, even if not using the same style of play.
So in answer to the thread title I think we have perhaps reached the tipping point in terms of the playing style, whereby things will now continue to improve on the whole and it will be more about the quality of the players as to how much of a success it becomes.
EDIT - the caveat to this goodwill etc is that this tipping point improvement has only been seen in the last month along with the change to the shape in midfield to achieve better balance, and has yet to be fully tested against top level opposition. It is a shame perhaps that we had not made the changes prior to the games v MC and LFC in Jan.