Overlord has posted a new blog about the future of the branches. I'll point out some of the more interesting questions and answers, I hope hope he doesn't mind. Not all of them, so feel free to read it for yourselves. As always, the questions and answers are modified to be comprehensible (and to remove typos).
Q (Vipez): Why don't you (instead of new trees) complete
the old tech trees and stop putting in more nations... atleast until
the "big 3" are complete with all their tds and heavys and stuff?
A: Heh, I believe they are never complete :)
Q: Italian tanks in the EU tree? A must!
A: Sure thing, they are.
Q: Do you plan to add more SPGs?
A: Each tree should have them. Plus there will be tier 9 and 10 SPGs. No ETA, sorry I don't do that.
Q: Have you considered the wheeled armoured fighting vehicles?
A: Nope, not considering them at this stage.
Q: 8.4 content?
A: I have checked with Storm - he says 8.4 will bring British TDs.
Q: Overlord, what about Polish branches? Is there any?
Polish and German communities on EU are approx equal in numbers. We will
definitely include Polish tanks - however at this stage it hasn't been
decided how exactly. It can either be a separate, rather tiny tree, or
some substantial part of common EU tree. The same as Italy btw
Q: Do you have already the materials for the Japanese and the EU tree?
A: For Japanese - yes, for EU tree - partially. Japanese will likely come first, the way we initially announced it.
Q: On the topic of Chinese tanks being brought in...
to account of interests of varios servers and regions - RU is the
largest, China is second largest, EU - 3rd, US - 4th. We also have SEA
and Korea, both are growing fast. Thus most of the decisions are
dictated by global vision.
Q (by me): A rather long question
Japanese tanks - earlier in 2012 (nov/dec) there was an info by SerB
and Storm that they managed to secure some new Japanese archive and that
they still missed the plans for top tier heavies at that point. Does WG
have enough data to implement top tier Japanese heavies now?
Polish tanks - there was an info (by SerB I believe) that he had enough
data to implement tier 7,8,9 Polish tanks, is that so, or was it just
c) Is there a candidate considered for tier 10
Polish tank (of any class, something else than the funny Lem tank), or
are they still looking?
d) Is there some other candidate for tier 10 Italian tank than the M47 Patton (with the 105mm L7)?
e) Are there any hightier (7,8,9,10) Hungarian tanks available WG found about or are they still looking?
a) As far as I'm aware there is still not enough reference material to
make up the whole tree, however our guys do know where to dig and whom
b) In my opinion, up to tier 7-8.
c) Nope, there is no such candiadate. That tank was more of a joke.
d) We are not considering Patton at this stage.
e) As far as I'm aware guys haven't found those yet, however they haven't been working a lot on EU tree.