You've heard it in the season 1 finale (when Damon kisses Katherine, thinking she's Elena). So many people loved it that Stateless decided to make a new version free for download on their site.
http://www.vampire-diaries.net/tv-series/download-new-version-of-bloodstream-by-stateless-for-free
click on the banner. You have to put your e-mail address. Once you've written it, just click on the link and download the song. Afterward, if you don't want the newletter from Stateless, just delete the message in your e-mail inbox.
Source: Vampire-Diaries.net
Subject: Bloodstream by Stateless 
Thu May 12, 2011 1:42 pm