iTunes store seems to be down all over the world. You must not be able to Download any Apps,Music,Movies and Podcast due to this outage of iTunes Store.
This thing was first noticed by Engadget.
Want to download the latest Engadget Show from the iTunes Store on your Mac or PC? Well, you probably can’t — right now, at least. That section appears to be down for most of us at the moment, with the Podcasts tab presenting a “not enough memory available” error message on each click. We’ve confirmed the error on iTunes 10.2.1 and 10.2.2.12 — the latest version — and aren’t able to get past the home page.
After hearing the new I also tried to Download but getting the same Error. Apple Team for sure must be working on the fix. So just wait a little and the fix should come out soon.