It should be if you meet the requirements described in the article:
- This program covers affected ATI Radeon HD 2600 XT video cards three years from the original date of purchase or until July 31, 2011, whichever provides longer coverage.
However, since these cards were last used in the 2008 Mac Pros and the next model came out in early 2009 I would find it unlikely your card meets the requirements unless you bought a refurbished Mac Pro or bought a 2008 Mac Pro the had been sitting in someone's inventory for a very long time.