Here you can find a recording of David's Q&A during Falkon 2014 in Poland.
Also during the signing, after the people wanting David's signature got what they wanted, I and some other Polish fans had the pleasure of talking with David for about half an hour. Here are some points :
1. Empire of Man no. 5 - David is waiting for John to finish the first draft.
2. Brandark's God and how he "got religion" will be probably revealed in the next Norfressa novel or it could be turned into a ~50K word novella.
3. Sahehold - David is planning to wrap up the current war in 2-3 books (including HFQ which is already turned in), than 2-3 books for the millenium visit war / resolution. There will probably be no book dealing with the Gbaba, but instead there will be an extended epilogue where we will see the end of that plotline.
4. Honorverse - the main storyline should be finished in 2-3 books. If He decides to pick it up again it will be ~30 years in the future.