The lack of in-depth management modes means you'll have finished the game before the real thing has run its course.
What is for sure is that the customary EA polish is here, along with the online features we have come to expect from the franchise. Graphically, the player models look a little sharper than FIFA 08, probably down to the reduced amount of players available in the game. The addition of short cutscenes showing the remonstrations and frustrations of the managers on the touchline is a refreshing add-on, as is the feature which enables changing of the goal celebrations in real time, although the modelling of the fans leaves a little to be desired compared to 08. Furthermore, on the PS3 version at least, there is a noticeable drop in frame rate in the instant replays, although nowhere near as bad as the latest Pro Evo offering on the same console.
Gameplay wise, the EA effort has never felt so much like Konami's Pro Evolution series in terms of smooth control and a refreshing lack of gimmickry. Sharp and intuitive, the controls seem to have been tuned since last year's version.
However, the reason I would say "rent it first" is that the lack of a manager mode of the like seen in the full FIFA games means that playing through the tournament with your given team a couple of times may exhaust your interest in this version of the franchise. Online features are of course fun, but the lack of real longterm appeal means this, like the tournament it represents, will probably have run its course by the end of June.