I bought my Mac Pro early 2008 and I wanted to buy a new 1 TB internal hard drive from apple.com. The one they sell says:

Requires Mac Pro (early 2009) and Mac OS X v10.5.6 or later

Isnt a 'Serial ATA 3Gb/s, 7200 rpm' a 'Serial ATA 3Gb/s, 7200 rpm'?

Whats so different about the new Mac Pros other than the 8-core?