At GDC panel, Rovio announced that Angry Birds St. Patricks Day is coming soon as part of Angry Birds Seasons. Little flingable leprechaun birds would as happy as well. Expect it sometime "Well before St. Patrick's Day." The new levels are expected to be a free upgrade to the free Angry Birds Seasons game, which is available on Android, iOS, Symbian and WebOS.
They also spoke briefly about the Angry Birds Rio game, meant to tie-in with the upcoming animated film. "We could make it work nicely with Angry Birds and the backstory. It could be the first time the birds leave the island, and are kidnapped by smugglers. This is not one of these lame movie games, but a separate game that works nicely with teh movie."
St. Patrick, is the patron saint of Ireland. Green is national color of Ireland, which is why everyone wears green for St. Patrick's Day, and thus why the new Angry Birds levels will be green too. The game is expected to arrive "before St. Patrick's Day," March 17
Angry Birds: Rio, which accompanies the big-screen film of the same name, is also due out later this month.