I've heard from several sources (mostly New Zealanders, admittedly) that Oracle didn't just tweak their trim, but fitted active stabilization to their foils.

After just now doing a bit of Googling – it's pretty clear all the rumours I'm hearing are all based of (and contain verbatim chunks of) this:

http://www.sail-world.com/Australia/Americas-Cup:-Speculatio... http://www.scoop.co.nz/stories/HL1309/S00253/americas-cup-la...

Not sure how much truth there is in that claim – or even if it matters much, but there's clear;y some controversy about why Oracle got so much faster after race 9…