NASA needs to get on with the program and get rid of the daylight restriction:

NASA could reconsider restricting this flight to times when the shuttle and external tank, upon separation, are lit by the sun. That was a post-Columbia rule intended to provide good pictures of the tank and its insulating foam to make sure safety changes worked to eliminate dangerous debris. It was supposed to be in place for the first two post-Columbia launches. After the 2005 return to flight mission saw a large piece of foam debris, NASA decided this third post-Columbia flight also would be limited to daylit launch opportunities. If NASA sticks to the rule, there could be just three days the rest of 2006 meeting all safety requirements. Indeed, it could be February before another viable launch window exists that meets the daylight and other flight rules. NASA officials on Sunday were given the opportunity to rule out the possibility of simply eliminating the daylight launch restriction for this flight, the agency did not rule it out. That could open many more days in the latter half of the year to avoid a potential five-month delay in the resumption of space station construction.

Emphasis mine.

They know they have the capability to inspect at ISS now, and most of the major foam fears should be laid to rest. They need to fly as often as possible, particularly given that it's hurricane season.

I don't see the point either. Surely it's safer to launch under these conditions than to delay launches months at a time. This collectively delay the whole launch schedule, right? And you end up with all your vehicles a few months older over their working lifetime.

And if something happens... then NASA rushed to flight without taking all precautions. I disagree with the daylight only rule, but I understand where it comes from. If NASA had gotten photos of Columbia via satellite, then it would have more information to calibrate the actual danger of foam debris. Does 1 sq in of foam 1 sq ft, or 1 sq yd cause catastrophic danger? If all you see is then big dent, but not what caused it, then what do you really know?

That's the mindset, but I still agree that is overly cautious. With only so many shuttles left, the information would not be so valuable. Besides, a nifty way to get the information would be to launch unmanned rockets and intentionally cause damage to get the information. Considering the cost of delaying shuttle launches by months... it might be cheaper.