I also would love to see Sophie chosen. I think she'd be an ideal choice, for several reasons. She certainly seems to get along with Kate, and I assume she gets along just fine with William as well (or at least I don't have any reason to believe otherwise). I also think that Sophie would just be good godmother material generally: I think she sets a good example generally, as well as in her role as a royal, and she also just seems like she'd be an attentive/enthusiastic godmother. (Also, as an aside, I didn't realize that William and Kate had visited Louise after she broke her arm. How sweet! I remember the pictures of Louise sitting next to Kate and William at the Olympics and Paralympics, and she seemed to be happily chatting away to them, so, despite the age difference, they seem to have a nice relationship).
I can see many reasons why Anne would be a good choice, too. However, I wonder if they'll continue to choose godparents from the same immediate family, or if they'll branch out more (I know it doesn't really matter, it's just that William and Kate have so many potential godparents to choose from). Also, yeah, I'm not sure how close William is to Anne, but then it can be hard to tell with William, as he tends to be reserved. Unless I hear something specific about William's relationship with a family member, I generally have no idea who he is or isn't close to (aside from Zara and Peter). Really, I'm prepared for just about any member of the family to be among the godparents
.