I'm really surprised at Dragon Age being up there. I'd figured the dearth of product releases for it would've doomed it well behind Warhammer or other games.
Perhaps the impending release of Dragon Age 2 (the computer game) gave it a boost in interest and drove some sales. It is not like there are a ton of obvious competitors and it is a pretty inexpensive set (nice production quality too) so that might not have hurt, either.
I do think the lack of the second boxed set is a serious concern for the future of the line (especially given the material it is supposed to cover).