Interesting questions. I think if whoever it was had wanted to speed decomposition they wouldn't have left the body inside the plastic bag, etc. And at the time of Caylee's disappearance, the water wasn't there yet, right? Then when the storm came, no way of knowing how long the water would remain high. (As far as I know. I'm not sure.) To me, although KC could have done it of course, it seems more like someone less closely related. The style of disposal, etc, just in a trash bag and simply dumped there on the surface, apparently not far from the street. The question that sticks in my mind is why leave the body in the Anthony's own neighborhood? (I don't care what the screechy voiced psychologist on NG says, I think if KC did it, that's the last place she would place the body, where it would create the impression of a link to herself. If she was going to dump the body, seems like it would be somewhere it wouldn't be found or somewhere more in keeping with her story about the nanny.) Even if she had initially dumped the body there in a panic, she had a whole month to move that bag somewhere it wouldn't be found. Well, one thing's for sure, whether or not this is Caylee, this is a little child who somebody dumped there. Just too sad to really comprehend.
Hopefully forensics can determine how long it has been there.