iTunes Plus DRM-free Tracks at 0.99€?

Following Steve Jobs' Thoughts on Music, EMI and Apple announced the availability of DRM-free tracks on the iTunes Store in May. Such songs, known as iTunes Plus catalog were initially sold at 1.29€/track while the price of the album remain unchanged, while featuring a higher AAC encoding quality (256kpsthe).
EMI was quickly confirming that iTunes Plus tracks were selling well.
Today several readers reported to have spotted songs from the iTunes Plus catalog available for 0.99€. Ars Technica reports that Apple is working on a project to expand the iTunes Plus catalog with other labels including indies while dropping the price to compete with similar offer from Amazon.