I haven't had the time to look at the recent
changelog entries closely but it seems to me that:
1) The S+ account level will be available to communities.
2) Communities will be able to be advertised in other communities. ETA: s+ and paid comms only.
3) ETA2:
link. Owners will be able to choose their option (promote and be promoted, promote and don't be promoted, don't promote or be promoted) in some manage section.
4) ETA2: According to
burr86, some communities will be banned from promotion by the site administrators.
References:
A,
B,
C,
D and
E among others.
Exciting stuff, right? ;-) Now that nameable permalink looks nifty...
P.S. And, as for ad-targeting, the number of notable interests has been raised from 10 to 150. Let's put a little variety in our ads, shall we?