I honestly doubt that this is even legal and will hold up in a court. Not a lawyer or living in the US but still if it would hold up every company can just place that sentence in their user agreement and no lawsuits would be possible anymore.
Well it is concering and with all the problems im reading about I will stay away from Polo.
"ADDITIONALLY, YOU HEREBY WAIVE YOUR RIGHT TO PARTICIPATE IN A CLASS ACTION LAWSUIT OR CLASS-WIDE ARBITRATION. "