I don't know, I can go both ways on this.
There's not a ton of protection on that team when he's sitting in the 3 hole. Or at least I don't think there will be, as I'm not sold on Cantu doing this all year. If you put him back in leadoff, at least you might be more worried about picthing around him.
Then again, I've always liked having a little speed out of your 3 hitter. Should the top (and/or bottom) of the lineup fail to get anything done, at least your 3 hitter (if he gets on) has the option to steal and get into scoring position for the big boys coming up.
With that lineup, I've got to come down on the side of leadoff, especially if Cantu keeps producing and Uggla does what he's done the past couple of seasons.