I know a lot of people have wondered about who cowl is. Some people wondered who was driving the car that hit Harry. Others have wondered many other things. If you can have one question answered in 12 months what would it be? ...
I think my biggest curiosity has to be around the whole "Starborn" thing.
I don't really think 12M is the place where we'll learn that, however. We know LtW and RS are both potential "tutors" / info-sources, but I think that's too much an outside-Chicago story-arc, when the book is heavily about Harry leaning-into becoming "the Wizard of Chicago" more fully.
I think (I've shared this theory here before) that a huge part of Mab's motivation, in ordering the marriage, is to aim her Starborn Winternight at the
Nemvector lurking within the White Court. Papa Raith is known to have amassed a substantive library on the Outsider/Starborn apocalypse-cycle, and I think Harry will get at least some peeks into that (a secondary element in Mab's planning: she knows of the library, wants her Winterknight better-equipped as an anti-Outsider weapon, and "knowledge is power.") ... I am hoping/expecting we'll learn at least
some snippets from an arc on this topic.
I suspect Bonea has a goodly bit of Starborn info... but I think Jim will dribble out the Starborn info slowly (into and throughout the BAT) so we won't get to the "Angelic-level" secrets known to Bonea this soon. So, Bonnie will still be in "figuring things out" mode, and likely unable to give Harry useful info there.