Could have been way better - but still fun!
The game I have to compare it to is NFS ProStreet, which is another somewhat "shallow" racing game for the Wii. That game I paid 15$ for and that is about what Dirt 2 is worth. I rented it for a week and quickly finished the championship mode - however I do find it a fun game when I have about 30 minutes to play. Some of the tracks/car combinations are challenging and it is difficult to keep up with the AI drivers, so I just keep going back to them. The Ethiopia circuit is a good example where too much power makes you easily airborne.
My verdict - wait until it shows up for < 20$