I ended up ordering one of these croc bags from shoebuy.com - I'm not sure it seems like it might be a little big for WDW - it's bigger then the baggalini.
It's a nice bag, and you can personalize it with the jibbitz. The strap is adjustable with a max length of 48 inches. there are two water bottle holders on each side. The bottom of the bag is approximately 4-5 inches. The bag itself is approximately 13x13. sorry for the approximates I only have a ruler here at the office. The pouch on the front has a key fob and a couple pockets and 3 pen holder slots. The inside is nylon material lined and has a cell phone pouch on the side at the top and the back has a zipped pocket. Otherwise no other dividers inside. There is a velcro pouch in the back the size of the bag.
Hope it helps someone that isn't able to find it locally. I'm not sure about carrying at WDW, I'm going to take it home and test it out but if not it's a nice school bag. It would probably fit a smaller laptop.