The rumour is they'll release Vertigo to Itunes on the 27th of September giving them just over a month of downloads, then come November you'll be able to buy all the CD's with all the b-sides and the DVD single as well (they know you'll buy it, let's face it, the download just ain't gonna be enough). If this is true, it's very clever marketing.
I mean if you look at it, you have the single radio / Itunes (if true) release Sept, the video will premier on MTV October, the CD single release the start of Nov and then the album a couple of weeks after that. That's a lot of U2 over the next few months. If you look at it that way, it's not madness to play Vertigo on the radio in a couple o' weeks.