Tamina makes sense. Haven't been keeping up with Smackdown lately ('lately' as in the past few months), but didn't her and AJ 'break up' on that show a couple of weeks ago?
It doesn't make a whole lot of difference to me personally who becomes champion and who doesn't, as it's an incredibly boring division imo anyway. In fact, I hope they have Tamina squash AJ in less than a minute (which I could easily see them doing for some reason... the longest-reigning champion of all time struts in cockier than hell that it's gonna be just another title defense, but then gets destroyed in what could end up being the shortest Diva's Championship in WWE history... actually, I quite like that idea, as we would be ending one record and setting another at the same time, a fitting moment for an event like Wrestlemania XXX) just so that we can devote the least amount of time as possible to the Diva's at Wrestlemania.