If they do Beyond, they should do it right, and have it as a one-off film that is set in its own universe. Not Burtons, not Nolans, not Shumachers, not even the next series. I used to think it was a good idea to string it to Batman/Batman Returns but they shouldnt confuse things only because it would be cool to get Keaton back in the franchise.
As far as im concerned, when this next series is over with. In say..10 years? I hope WB starts adapting comics to live-action, and concepts like Beyond. A Batman Beyond adaptation, a Batman: Year One set in the 70's, possibly a Killing Joke or Dark Knight Returns adaptation eventually.
I think by the time we get Beyond, there will be no possibility of choosing your Eastwoods, Fords etc. Maybe Alec Baldwin could be good or maybe the actor to play Bruce is an actor in his 50's currently. And our Terry McGinnis is just a teenager at the moment who may or may not have started in the business yet.