Anyone really believe there wasnt some fine print somewhere saying Harrah/ESPN has the right to alter, modify, and/or cancel said event? just because it wasnt advertised to you doesnt mean it wasnt there.
here is the rules for this years events ill assume a similar rule is around for the ToC players to check out.
http://www.worldseriesofpoker.com/rules.asp
(be sure to check out rule 11)
Im not saying its right but the reality of the situation is its there show and they will run it how they see fit.