Sorry to be the (belated) bearer of bad news, but we were denied. We had one Tyvek ticket, and one WDW room key with a one day ticket on it, and were unable to use either one. The CM at the gate seemed to know what she was talking about, and said that while they used to accept WDW tickets, the powers that be put a stop to it about a month ago (sometime in November, 2013). She said she could go get a manager, but he or she would just tell us the same thing.
We had prepared for this contingency by buying a gift card to pay for my dad's 2 day, 1 park tickets (our family has AP's). We just had to go over to the ticket window and buy them before going into the park. It was disappointing, but we didn't let it put a damper on our trip. We had a wonderful time, and will just save those tickets for our next trip to WDW.
Sorry everyone!