Sharpie
Danjohn, an adcom member addressed the 30% increase in another forum and stated that this info isnt shared until the end of the complete admissions cycle. This figure is entirely speculative.
Speculative? - probably. Yet I think ~30% increase in EA makes sense - for two reasons:
1) GMAC reported that a lot of candidates rushed to take the test before the format change this year. Folks who would have otherwise put off until July or August had their scores ready before June and had ample time to work on their apps. A corollary that follows is that early apps % must have been higher at other schools too (we just won't know until the cycle is over).
2) Tuck has been ranked 2-1-2 over that last three years by Economist (up from 6th and 5th in 2008 and 2009). Although I am not sure how big these rankings are locally, I can speak for internationals who take these rankings very seriously. I'm guessing the increased visibility and consistent rankings led to more apps from candidates outside the country.
Granted all this is based on theories and inferences and there is nothing we can do about it even if it were true

All I wanted to say is that there are factors that support this figure - I wouldn't be surprised if an adcom person had a slip of tongue and said that out loud