The Fitzgerald investigation

From ABC's the Note:

The Fitzgerald investigation:
It turns out, per the Washington Post, that Bob Woodward testified under oath on Monday at Patrick Fitzgerald's request. LINK

The lede:

"Washington Post Assistant Managing Editor Bob Woodward testified under oath Monday in the CIA leak case that a senior Administration official told him about CIA operative Valerie Plame and her position at the agency nearly a month before her identity was disclosed."

The Post story and Woodward's statement raise as many questions as they answer.

The big ones:

1. Why is this happening now?

2. Who was Woodward's first source?

3. What is Fitzgerald looking for?

What we know: Woodward got a waiver to speak from the source. Woodward will only say it was not "Scooter" Libby. Who has granted waivers in the past? Karl Rove. (At least to Cooper.)