Most of the time, the specific photo needs to be seen to determine how bad and what the best means would be.
However, sometimes in the transfer to photo cd’s, a channel can offset and give a pusedo-color cast that looks like blurring. So, check the individual channels first to see if you need to nudge one some direction.
Something I’ve had pretty good success with is using the Smart Blur filter then the Unsharp Mask. Different recipes for different items, but short of exact selections and massive retouching via rubberstamping, contrast/level adj’s and the like those might help you out.