So, Imagineer Scott Malwitz gave interviews during D23 about the Fantasyland Expansion. His given timeline for the openings are as follows:

Early 2012 (Jan-June) - Half of Storybook Circus with double Dumbo, Great Goofini coaster, Fantasyland Train Station, Casey Jr.
Late 2012 (July-December) - Under the Sea ~ Journey of the Little Mermaid ride, Be Our Guest restaurant, Beauty and the Beast village, Belle meet-and-greet, Castle wall
Early 2013 (Jan-June) Remaining half of Storybook Circus with Pete’s Silly Sideshow
Late 2013 (July-Dec) Seven Dwarfs Mine Train roller coaster

He also said the big stuff wouldn't open all at the same time, but within a few weeks of each other. Obviously Disney wants to get all the publicity they can so they might open Little Mermaid one month and Be Our Guest the next month. No specifics are given, though, so we'll have to wait and see. But, for those of you planning on heading to WDW next year, there's a general idea of what to expect straight from one of the Imagineers overseeing the project, making it not just a rumor. Obviously this is all subject to change, but there you go.