Look, we all know there is no basis for prosecution of Rove for outing a CIA agent. What I'd like to know for sure is whether or not Fitzgerald can widen the scope of his grand jury's investigation. In the old days of the Independent Counsel the AG and/or the courts had to officially be requested to allow that. I believe a grand jury can go wherever the investigation takes them. If that's true, then it's very noteworthy that Joseph Wilson has never testified before this grand jury nor has his wife. It seems a particularly simple task for Fitzgerald to question her as to when and where she was "covert" since this seems to be a major bone of contention. That tells me that he/she could very well end up being the target of this investigation since it's not unusual to have a target not be questioned before a grand jury that's possibly going to indict him/her. After all, no lawyers are allowed in the room and pleading the Fifth becomes a nuisance, albeit a constitutional one. However Wilson and/or his wife may have already been questioned by federal officials outside the grand jury and those officials may have testified.
As an aside let me say in light of Wilson's rather questionable personal business dealings and qualifications for going to Niger on behalf of the CIA in the first place, along with the fact that he never filed an official report upon his return, there is the distinct possibility that he could be guilty of much more than simply obstructing justice or perjuring himself. Links to individuals involved with the Oil for Food Scandal along with suspect uranium dealings could very well be much bigger fish to fry.