Actually, I think they don't name you as a target until right before (or simultaneously with) indicting you. I'm sure they know you are a target from day one, but don't want to make you an official target, because they want to get you to cooperate with them and perhaps give them information they can use against you or someone else. I had a friend who was never an official target but was indicted at the 12th hour on the last day of the statute of limitations. Perhaps they called his lawyer that day to tell him he was a target
In this case, we know there was no official crime (like the bogus naming a covert agent crap), so the only thing the prosecutor can do if he wants to get someone is try to get them for perjury. He can't get them for perjury if they don't testify, so he can't name them as a target until the end.
The only way that Rove will be indicted is if Fitzgerald is part of the democratic conspiracy to alter the 2006 elections by painting the republicans as having a "culture of corruption". Some say Fitzgerald is a professional and wouldn't do this, but he is a democrat and he may also be looking for some big star to put on his resume for future elective office.
Judge Andrew Napolitano, on FOX News, said the same thing.
Thus, I can't believe he'd go after Rove or Libby on a trumped up prejury trap. Perhaps he's planning on blowing the cover off the media conspiracy to bring down Bush, and will indict Cooper and Miller.