Hi Laura,
We are all very eager for news of the renovated and expanded Fantasyland. Unfortunately, we don't have very much to tell you. There have been no formal dates released for the unveiling of future attractions other than "late 2012" or "sometime in 2013."
If I had to guess, I'd say that the new Ariel attraction, the Be Our Guest restaurant, and the Seven Dwarfs Mine Train will be open on the earlier end of that span. (Again, just a guess, I have no inside scoop.) There are new princess meet and greet areas that will be part of Fantasyland, but construction on that has not even begun yet. The meet and greet areas for princesses will be sited in the location now occupied by the Snow White's Scary Adventures attraction, which is currently still open and slated to close on May 31, 2012.
The best I can tell you is to keep checking back with us and keep an eye on the official
Disney Parks Blog. When there's new information to be had, they'll let us all know about it.