In general I would agree that Darcy seems to be still (or again) undecided and having qualms about proposing, but then we have this in ch.32:

"...in speaking of Rosings, and her not perfectly understanding the house, he seemed to expect that whenever she came into Kent again she would be staying there too. His words seemed to imply it."

Of course, Elizabeth misunderstands him and thinks he's alluding to Col. Fitzwilliam's intentions, but to me, this particular instance sounds like a man who has already made up his mind that this is the future Mrs. Darcy; he just hasn't gotten around to the formalities yet. (I'm reminded of an older friend, a minister's wife, as a matter of fact ;-), who described her first boyfriend as such a lousy communicator that he bought a camper to take her on their honeymoon before he even asked her to marry him. She said no; he still took the camping trip, but took along her brother instead of her! ;-)