The August 17 re-release date for Greatest Hits I is apparently tied into the US debut of "We Will Rock You" on Aug. 16. It will reportedly include live versions of "Under Pressure" and "Tie Your Mother Down," as well as the new version of "I'm In Love With My Car" featured in the Jaguar commercial.

Read more about it on the Billboard website:
http://www.billboard.com/bb/daily/article_display.jsp?vnu_content_id=1000580040