I hope they will, this show has been spoiling me with MORE Watanuki x Domeki scenes than the manga has ever provided!
Episode 21, Watanuki acts just like a housewife for a guy who just busted into his room. I'd call the police or something.
And, for those who have read the manga, we all know there will be at least one more scene just for this coupleÂ
And, of course, XXXHolic shouldn't end without another important arc.
Actually, I feel that XXXHolic may last longer than Tsubasa in anime because there're so many problems in society and so many things wrong with people out there, particularly psychologically, they can make TONS of filler episodes. (I can't believe the dark, MTV generation that I used to pick at becomes such a morbidly beautiful inspiration :p)