I suppose that this is really a sign of the times, and a sign that music gaming has really ended. Man, why does it seem like only yesterday I was playing Rock Band and thinking this was the best thing in the world. I guess it really shows that no fad will really last forever.
You have until March 31st to purchase downloadable songs for the music-based games, and they will be going on sale. By the way, all of the songs that one has purchased before the deadline will be available for all of the current platforms and more.