Too much money involved, they are both on course to make weight, the fight wouldn't be stopped for the sake of a few pounds, only Ricky's titles being on the line if Pacquiao doesn't make weight.
Hatton cuts easily and has been cut early in a few of his fights. So yeah, if he got cut early this time and couldn't fight properly then that would be crap!
I think the worst case scenario would be if they head butted and the fight got stopped on cuts at any point, especially early. Otherwise, it would suck if either scored a quick knockout. I'd like to see this one go into the later rounds (atleast into round 10). I'd like it to be similiar to Sugar Ray Leonard vs Tommy Hearns with the back and forth momentum.
Pac gets frustrated by constant Hatton wrestling and bites off part of his ear. Not good for either guy.
Once you get knocked out by a ringpost, the worst thing that COULD happen to you in a fight already happened. As for Pac, I think getting KOd would raise a lot of questions about his durability above 135.