Cool. That was one way we were thinking about it but it seemed so unfair to roll a 35 acrobatics check against one person and a 6 against the next one that some of us were entertaining the idea that it might just be one check against multiple creatures instead of many.
We've been playing and have a question about whether someone needs to roll for each creature they would be moving through a threatened square for. Example: A rogue is tumbling past 3 baddies...does he make 3 Acrobatics checks or is it just one and the penalties for multiple creatures just stack against that one roll?