Blurry isn't a bad song. It caters to both rock and emo bases, and makes a change to the numetal music that has been through the charts lately.
However, it falls short in a few areas. The contrast between the verses and the chorus is a little over the top. They could have done with keeping turning down the amps a bit for the chorus. The constant jumping between heavy guitar and screaming vocals and nice guitar and pleasant vocals is somewhat disconcerting.
Add to this that this sort of music is not original by any means. The Goo Goo Dolls have been producing music just like this, but better, for years now. So, Puddle of Mudd.. they're a good passing distraction, but they're not revolutionary, and fail to improve the style in which they operate.