Exactly. I've been thinking the same thing (great minds, you know......). Too many are guessing (it's fun, we all love to do it) but it may well be that the change is proceeding according to a well-ordered plan, and that Pres. Bush will announce his new nominee soon, in a time and manner of his own choosing. Still, the usual pattern, I think, is to announce a hand-off with a new nominee present, with the Pres. between the departing official and the new (nominated) official. But I can think of several reasons they might not choose to do that, even if they had had time to work this through.......
It is possible that one or more of many investigations are beginning to focus on Congresscritters with whom Goss associated and did battle. If so, he would have to step aside to remove the political witch hunt aspect of the investigations.