Sounds kind of strange to me. First, if one Shuttle is stranded in orbit, what's to say that the same thing wouldn't happen to the rescue Shuttle? Odds are they wouldn't have time to investigate the cause of the first Shuttle's problem and implement a fix within that amount of time. So, in the event of an in-flight emergency, are they going to roll the dice and hope it doesn't happen again on the rescue flight?

Second, NASA has decided not to launch at night any more so they can more closely monitor the Shuttles during liftoff using long range cameras. The problem is that really reduces the number of launch opportunities to the ISS, especially in the winter. Will they also launch at night to meet the 45-90 day projected timeline? In short, will they throw safety out of the window for the rescue flight?

I also wonder how this will impact launch processing in the VAB. With only 3 Shuttles remaining, how will they manage the processing to always have a second orbiter ready for flight within 45-90 day timeline? Or, is this only for the next flight and not for all Shuttle flights?