If you purchase a copy of Acrobat Pro version 9 on or after 10/18/2010, you can contact Adobe to get a free upgrade to Acrobat X Pro. You can do so by following the instructions here:
You have to contact them to get the upgrade; they will not send it to you if you don't.
Acrobat Pro Extended is being discontinued. If you purchase a copy of it on or after 10/18/2010, you are eligible to get a free upgrade to Acrobat X Suite (http://www.adobe.com/products/acrobatsuite.html) by following the instructions above.