I also know that Kenneth Branagh was interviewed for the directing job of PoA.

Alan Rickman has also previously directed "A Winter's Guest" (starring Sean Biggerstaff and Emma Thompson) so possibly a collaboration between those two directing together might be a good choice.

I also think Emma Thompson who won a golden globe/BAFTA for her screenplay writing on "Sense and Sensibility" might also be able to script HP. She did a fantastic job on the Jane Austen novel so she has experience and her being a somewhat minor character it probably wouldn't interfere with her acting in the film.

I'd also like to see Alfonso back, possibly for one film, maybe the 5th as that appears to be an emotional story too, although there is qute a bit of action toward the end.

Wolfgang Peterson (King Arthur), Gore Verbinski (The Ring, Pirates of the Caribbean) and Jerry Bruckheimer (Produced: Armageddon, Pearl Harbour, Pirates of the Caribbean and King Arthur) may be good choices too.