Predictions with reasoning:
2011: Chopin (AoS 1) and Buckley (AoS 3)
2012: Bernstein (AoS 2) and Yiri (AoS 4)
2013: Mozart (AoS 1) and Moby (AoS 3)
2014: Reich (AoS 2) and Rag Desh (AoS 4)
2015: I would assume from the pattern that it would be two set works from Areas of Study 1 and 3. Since there are three works in each AoS and we've already had two from each, I'd assume it would be Handel and All Blues.
That said, it would be handy to note that they have not tested: Handel, Schoenberg, All Blues or Capercaillie. Edexcel might realise they've given the game away - especially since this blatantly obvious pattern actually TELLS candidates exactly what questions they will get. Therefore, they might throw a curveball at you. So be prepared for all of those questions.
Anyway, does that sound vaguely logical?