A compressed primary schedule usually favors the front runners. Early wins build momentum, and the compressed schedule means that there isn't much time for opponents or negative information to derail the train.
The problem (depending on your point of view) is that the schedule is set months before anyone actually votes. At that point, the entrenched party insiders (yes, I'm looking at you Senator Clinton, Governor Romney) probably have an advantage in fundraising and name recognition, leading to an advantage in early opinion polls. And, as party insiders, they have enough clout to have some influence over the schedule.
It's too early to say the scheduling strategy has backfired. But it is amusing to watch a couple of upstarts reap its benefits.