Major Nelson made mention on Twitter a bit ago that three new titles are now backwards compatible on the Xbox One. Two of them are Puzzle Quest games, including Puzzle Quest 2 and Puzzle Quest Galactrix. The third title is Sonic & All-Stars Racing. You should be able to grab them now whether you previously own them or wish to purchase them on your Xbox One.
You can check out every title that is backwards compatible over at Major Nelson’s site.