Just thought I'd post my most recent experience here since I asked for confirmation on the extension of the program. We have managed to collect enough for 4 1/2 round trips (family and friends passing their cups along and buying a bunch of them from a cub scout troop who went dumpster diving to collect cups and sell them to make money to go on some trip, they were selling them for 65 cents per cup). I was hoping to get 6 round trips...enough for our family trip to WDW and for DH and I's trip to Universal for our 10th anniversary. We would go to Wendys periodically and just have lunch. We'd sit by a trash can and if someone was getting ready to throw a cup away I'd ask if I could have it. I usually had like 5-7 cups (including the 2 or 3 for my kids and I) so it's not like I had a ton of them to walk out with. Today as I was walking in there was a lady walking out with about 40 cups that looked brand new. I asked if they let her buy a bunch. It turned out the manager was walking in behind me and she said yes, they would. She said they would be out of cups before the end of the night for sure and she was anxious to get rid of them. She was tired of people hanging out in the restaurant all day and asking if they could load bags of trash in the back of their trucks, tired of coming in in the am and finding that people had gone through the dumpster and making a HUGE mess for them to have to clean up etc. I asked how many they had left and she said only maybe 250. I ended up buying enough to finish out our 1 1/2 that I needed. She sold them to me for the cost of a medium drink, gave me a 10% "senior citizen" discount (I'm 34 so I am no where near senior yet!) and gave me our food for free. With the discount, even after tax, they were less than $1 each. I totalled up what I've spent (we've been keeping a running total) and it was about $245. Not bad for 6 round trips!
Anyway, these cups say through Feb and I asked about it. She said no, it was ending 12/31. That they changed the date back to 12/31 when they saw the reaction to the promo. They were sent new cups but OKed using the old ones once the 12/31 cups ran out. So at least according to her it has NOT been extended (which is what I was afraid of since the official page says 12/31).
She did say if your Wendy's still has them, that at closing on 12/31 they are supposed to throw out any ununsed cups...so that may be worth considering. If they have a bunch left they may be willing to give them away, or sell them for the price of a cup of water that evening.