When the Christmas special was announced, it said that one of the special's songs will air on Radio Disney. However, according to disneysociety, all of the songs will air on Radio Disney.
According to an iTunes podcast that can be found here, the soundtrack was released on December 7, 2009 (the day after the special aired on Disney XD) in the iTunes store and Zune Marketplace. MP3 downloads are also available for purchase from Amazon.com. A CD version has not yet been announced.
Just like the Phineas and Ferb Soundtrack, the songs are sung by artists or Phineas and Ferb characters. For example, Doofenshmirtz is credited for I Really Don't Hate Christmas. In That Christmas Feeling and Thank You Santa, Olivia Olson and Mitchel Musso in the show were credited for the songs instead of their respective Phineas and Ferb characters (Vanessa and Jeremy).
Despite only being available through online retailers, the soundtrack reached No. 21 on the Billboard Kids Albums chart on January 16, 2010 and spent three weeks on the Holiday Albums chart, peaking at No. 14 on February 6.