Possible DADA tachers:-
Snape will never be the DADA teacher, Rowling said so. She said that Dumbledore fears that it would bring out the worst in him. I am not sure on this next point, but someone reported that Rowling said that she was not going to introduce any new characters. 🙁
Lupin surely won't do it again, he has already had a go at it!
I think we may be having an echo of the pattern of the first three DADA teachers. The forth and fifth do have some points in common with the first and second. Rowling may be repeating the pattern of:
(1) Voldemort affiliate (Quirrel/Crouch)
(2) Fairly crazed and academically useless teacher (Lockhart/Umbridge)
(3)Good teacher, a mentor to the good characters, an ally to Dumbledore and a member of the Order of the Phoenix (Lupin and ???)
So the new teacher must be a good character, very likely of the Order of the Phoenix like Lupin. Who could that be? Tonks is a distinct possibility. Shacklebolt also might do it. Maybe even Bill Weasley, to show Ron that he needn't be like Percy to be a prefect (or even Head Boy). I would think it better if Moody didn't, as we have already had his peculiarities shown to us by the impostor Crouch.
Good question! 😄
I wonder if the post really is cursed... 😕
I think Tonks will be as well, and reason I say that is that she's probably still feeling some effects of the stuuners or whatever the spells were that knocked her out in book 5. She's probably on a medical leave from the Auror Squad or whatever they call it, and Dumbledore probably offered her the job on a temporary basis until she's recovered.