There is nothing 'sure' about an OGM. Yet, some fans are already crowning some skaters Olympic champions in 2014. Haven't we learned from the past? (e.g. Michelle in 1998, Irina in 2006, etc.)
For the 2014 Olympics:
I don't believe V&T are a sure bet for the OGM. pairs champions. IMO one mistake could cost them the gold. They have S&S breathing down their necks, and a few lesser pairs could take the spot if the two top pairs make major mistakes (e.g. fall on a throw, multiple falls of any kind during the program, leaving out an element, etc.). The fact that the Olympics are in Russia could work for or against V&T. The pressure on them will be enormous to bring back the pairs gold. Can they handle it? That may be the key.
This is as sure an OGM as you can get (like Hamilton in 1984). Patrick Chan will have to make multiple mistakes in both SP & LP, and someone else (Fernadez? Takahashi? Hanyu? Ten?) will have to skate lights out in both, and even that may not be enough. Chan can be beaten, but it's a very very low probability. It's sort of like 2006, but Plushenko could not afford to make mistakes on jumps; Chan can.
This is where things get interesting. Yu na should be the overwhelming favorite, but will she skate as great as she did in 2010? Based on how she skated at the last worlds, I think the chances are pretty good that she will land all her jumps. Her main challenger would be Carolina Kostner, but she will have to skate a perfect SP and a near perfect LP, with a 3-3 combination. I don't see anyone else as an OGM contender. Will one of the younger skaters beat both favorites, like in 2002? Gracie Gold, Sotnikova, and may be someone else? As much as I love Mao's skating, I don't believe she has the jumps to beat the strong jumpers at this point. She may land he 3A, but she is prone to ur or mistakes on the easier jumps. She will have to be perfect in SP & LP and hope that all other top skaters make major mistakes. I hope Ashley wins an Olympic medal, but I don't see her as an OGM contender. Still, the ladies field may be as open as any, if Yu na and Carolina make major mistakes.
In the past this used to be almost a no-brainer, with the 3-time world champion winning the OGM, but not so in the last few Olympics.
There are only two OGM contenders in 2014- D&W and V&M- and they are so evenly matched that it's hard to pick one. I won't mind it if they awarded a double gold in ice dance. Each has only 50% chance of winning right now. However, if one of them seems to be the judges' favorite during the season, that could tilt the balance in favor of that team. Barring injury (heaven forbid) this should be the greatest ice dance competition for the OGM. The rest of the field will battle for the bronze, and there are quite a few contenders for that.