It's a little sad to see how many folks mentioned everything but plot sourcebooks to move the storyline forward. It is kind of frustrating as a fan to see a community so focused on looking backwards. Particularly when the last two years worth of products has felt so heavily slated towards looking backwards. (Note: That's not to say it is, I haven't run numbers on that. It's just felt that way to this fan.)
I'd half agree with you- I really like the historicals since they cover areas that have not been well detailed before. On the other hand I hate the Era Reports- they just rehash the material I have in a dozen other source books. If they started during Era Reports for earlier times (1st SW, RW, Davion Civil War, etc) then I would revise my opinion.
I'm actually looking forward to the jump past the Dark Age- War of Reaving is the first non-historical BT that I have been interested in for a while now- knowing the outcome of the Jihad made the Jihad books only slightly interesting.