Old versions of GRE prep books?

<p>What's the difference between the 2008 (which covers the computer-based GRE) and 2010 version of prep books? Will buying a 2008/2009 Kaplan prep book, ie, be almost as good as the 2010 version? I would imagine that there would be little difference....</p>

<p>Thoughts?</p>

<p>Thanks!</p>