If Kubo ever actually does any Official Pairings, I figure it'll probably be Renji/Rukia and Ichigo/Orihime (I think he's really written himself out of and Ichigo/Rukia, by the latest chapters). I admit, I am fairly fond of those pairings as I have a thing for unrequitted crushes, but I doubt anything will ever happen with them (or anyone else) in the series. But, seriously, there's nothing in the book to really indicate that anyone will end up with anyone.