According to this flyer, the theatrical release of Puella Magi Madoka☆Magica will be split into 3 parts and two of them will be out this year.
Claris will be performing the theme song for “The tale of beginnings” and Kalafina will be performing the theme for “The never ending tale”
Claris has performed the opening theme for Madoka(TV), and has also done work for Nisemonogatari and also the upcoming Moyashimon returns.
Kalafina has performed the ending theme for Madoka(TV), their other works include, Kara no kyoukai and Fate/Zero and many others.
Part 1 of the movie, “The tale of beginnings” will commence 6th October 2012, whilst part 2 of the movie, “The never ending tale” will commence 13th October 2012, 1 week after the 1st.