A happy surprise in mobile iTunes

I went to go update my a app on my iPod just a few mins ago and found the purchases button and saw all my apps that I have gotten and so I went to iTunes and all the music I have boughten were there as well. I didn't know they had added that today I thought it was a iOS 5 thing but I'm glade they added it today. I hope to see the whole WWDC keynote latter.