In getting sidetracked in the U.S. Ladies thread I argued that a poster didn't deserve to be mocked for suggesting that no one was a lock for the Olympic ladies event from the U.S. The poster doing the mocking suggested that if we were going to even discuss that possibility, we might as well take into account the possibility of an asteroid hitting the earth. It would be considered an upset if Gracie and/or Ashley didn't make the team, but it's still early in the season, and even right now it wouldn't be a bigger upset than a number of others that have happened at U.S. Nationals.
1996: Rudy Galindo's win
2008: 14-year-old Mirai winning and Kimmie only being 7th (though we serious skating fans had known that Mirai had serious talent prior to that)
2009: Brandon Mroz finishing 2nd ahead of Lysacek (who went on to win Worlds that year), with Weir (who had won bronze at the GPF) finishing only 5th.
2010: McLaughlin & Brubaker finishing only 5th at Nationals, after being featured in a commercial for the Olympics and considered the heavy favorites for the title, and nearly locks for the team
2011: Ryan Bradley winning after not competing all season and only deciding to enter Nationals relatively late in the game, as I remember. Dornbush and Miner finishing 2nd and 3rd, and neither Abbott nor Rippon making the world team.
I also argued that if someone was arguing that Davis & White might not make the team, that it would be more understandable to mock them, because that would be the skating equivalent of an asteroid hitting the earth, and I doubted that any result in the history of figure skating had ever been as big of an upset as that would be.
Some other REALLY unexpected results that I remember:
Nobunari Oda not even qualifying for the free skate at 2010 Worlds, after doing fine at the Olympics and with no talk of any injuries.
(Lu Chen not qualifying for the free in 1997 was also surprising, but we knew she wasn't at her peak).
Laurent Tobel beating Alexei Yagudin in the qualifying round at 1999 Euros (OK, it was the qualifying round so Yags probably didn't give 100% but I remembered being really shocked by that ).
Kulikova & Markov displacing Denkova & Staviyski from the podium at Skate Canada in 2002 (the latter of whom went on win Bronze at Worlds that season). I do remember really loving K&N's free dance at that competition.
ETA: This probably belongs in the Trash Can now that I think about it.