I don't think it'll be bi-monthly. From what I've seen, companies will make release dates far apart so they have more room to work with. They don't want to make promises of monthly release dates in case something comes up, so they give out more spaced out release dates.
Also, in my experience, anime DVDs will generally have better features as releases come out.
I remember being really unsatisfied with the GTO extra features, but then around the third DVD I think it was, they had an interview with the creator which I really enjoyed. So, I'm guessing we'll eventually get those better features, we just got to be patient.
Besides, I think the box and CD more than make up for poor features.
Exceptionally bland and completely uninteresting signature here.