OK, I misunderstood.
I too am a bit puzzled as to why it was taken out. I really doubt if many beginning DSLR users even know about sensor dust. its only visible under certain conditions.
I wonder how much that component costs Canon to put in?
I'm not sure the fact that beginners don't care much about sensor dust is justification enough for removing it -- beginners are also more likely to "f/8 and be there" for general purpose shots, and beginners are also less likely to know how to clean dust on the sensor properly once its there. vice versa, beginners are less likely to ever take their lens off the body.
I do know that back when I was shooting with the 30D, I did at times end up with dust spots large enough that they showed up at screen-display sizes ... something a beginner wouldn't enjoy any more than I did, I expect (since they're also less likely to own/know photoshop). maybe canon is relying on better antistatic coatings? or maybe they're hoping to drive a few more customers up to the 60D?