Hurf...on the one hand, nice job kids, and that's a cool idea.
On the other hand, I hear enough choirs sing at work that I can't help wishing this were performed by a high school choir instead. Lacks the interesting detail of the whole innocent-youths-for-GlaDOS thing, which is admittedly pretty cool, but I've heard some high school choirs give absolutely spine-tingling performances.
Maybe in another few years when these ones grow up and have time to really work into the music we could get an encore?