We're hearing a Snow announcement could be coming in the next day or so. The names aren't radically different from what other people have been saying, though there is talk that perhaps the President is going to look inside his current Cabinet for the new Treasury Secretary. Nothing like the famous switcheroo President Reagan pulled with his team, but still, a bit of a curve.
As for Tony Snow, you read between the lines and it is clear that a number of people appear to be setting up senior White House counselor Dan Bartlett as the fall guy. For example, stories this morning are reporting that Snow wants "access" to the President and a chunk of responsibility currently under Bartlett's control. If Snow for some reason chooses not to take the job (and very people have ever said "No" to the President), it will almost assuredly be spun as Bartlett's fault or the President's fault for supporting a long-time adviser over a smart hire.