Beginning in late October 2009, Tiana, the African-American star of Princess and the Frog, will be holding regular character greeting hours in the Magic
Kingdom. You can read more about this on the WDW website
HERE. Additionally, from October 26, 2009 until January 3, 2010, there will be live musical production called
Tiana's Showboat Jubilee, featuring songs from the movie.
Tiana-themed merchandise should begin appearing in the parks during October 2009. I expect that it will remain available at least through the spring of 2010, if not longer.
Good luck with your planning.