The buzz on the web is that indictments will be announced tomorrow.
My best bet is;
Libby for blabbing Plame's identity to the press (Miller, etc.), and perjury (lying about it)
Rove for perjury, and maybe also for revealing Plame's identity, though my bet right now is that Libby gets the full brunt of that charge.
Cheney gets a pass. Why? Because he is allowed to talk to Libby about Plame (he is Libby's source), and because Libby had clearance. While everyone 'knows' that Cheney put Libby up to the leak itself, I have no doubt that he'll throw Libby under the bus to save his own skin.
But if Rove and Libby are all they get, that's good enough for me.