http://www.usatoday.com/tech/science/space/2005-05-31-deep-impact-focus_x.htm
"Deep Impact is on track to smash its impactor into a comet July 4, but its high-resolution camera's focus is still imperfect."
"The only disappointment so far is the High Resolution Instrument, the telescopic camera that was to provide detailed pictures of Comet Tempel 1 and the impact."
"The blurriness is still under investigation"
so there is a chance that we will crash a space probe into a comet, and only get fuzzy pictures? That kicks ass.