Good news for you. I was completely wrong and the regular set is already coming out on December 16. TV Shows On DVD has the news here: http://tvshowsondvd.com/news/Batman-The-Complete-Television-Series/20506
Yeah and Warners is doing it with the S2 DVDs (S2-Part 1 has been announced for February) so when/if the Blu-rays are sold as separate seasons, I assume they'll do the same.
^ My guess is that they'll eventually release the seasons separately (and probably with S2 split into two parts) and after that, they'll put those four individual sets in one standard box.