Important Announcement: In the event that Super Bowl XLVIII's date and/or venue is changed due to severe weather conditions, all existing open bets on the game will stand.
I'm of the opinion that if you made a bet on the game before the announcement and the date or venue is changed then they can't possibly make the bet stand if you complain about it as the rules clearly state that just the opposite of their announcement.
17. All sporting events must be played on date unless otherwise specified. If an event is postponed and/or rescheduled or a change of venue, the event will automatically constitute "no action," which means all monies for that event will be refunded (Unless sport specific rules state otherwise). All parlays/exotics will be recalculated excluding that leg of the parlay, using payout charts for that sport/betting option. Individual tennis matches have no action if the match is not fully completed due to withdrawal/incapacity or disqualification. If a match is rescheduled due to scheduling and weather problems bad light etc, then all wagers will have action and all wagers will stand.
I don't see how they can apply this new rule to wagers made before the announcement.