It'll force the IRS to issue some more detailed tax regulation on Bitcoin though. In my mind, that's a good thing, as it'll lend additional credibility to Bitcoin.
I don't see why... it's treated the same as being paid in gold or another commodity, really.
If someone goes and collects silver or gold at their storefront and does not report them.. see what happens... eventually they'll come knocking on your door asking how you paid your employees and how did you pay your social security taxes and your X and Y taxes...