Traded in my 2008 edition and picked up the 2009 version on Friday and have to say I'm not disappointed.
IMHO, the only element that was lacking in the 2008 incarnation was what felt like an almost random approach to defending. This time round the tweaks made to defending is a marked improvement. Now if you concede a goal, the chances are it was your fault and not the wonky AI.
One cool feature that was touched upon in a review I read was the ability to update a team, via wi-fi, to reflect their actual real life personnel.