Hard to say; Special Traitorgate Prosecutor Patrick Fitzgerald has been remarkably good at keeping leaks to veritable non-existence... so there is no official explanation for his asking to convene a new federal grand jury.
We can safely assume that "Official A", otherwise known as "Karl Rove" may still be in legal jeopardy, as the investigation goes on. Of course, until such time as he becomes the second sitting White House official in 130 years to face indictment (the other being Irv Lewis "Scooter" Libby)...
Frankly, given other crap going down today, including a former CIA director lauding Dick Dastardly, America's "vice-president for torture", House Republicans were so freaked by the traction John Murtha was getting with his call for a six-month pullout that they've scheduled their own straw-man vote calling for immediate withdrawal from Iraq, all while Iraq itself was having a very, very bad day... make me think that Dick and Roy and Bill and the gang can't wait for the calming influence of the President himself to return to American shores.
Because the White House and their allies in Congress... are not having a good day.