Rover

O'Donnell thinks that the meaning of today's testimony would be known if we knew whether Rove asked to go to the grand jury or if Fitz asked him to come. He says the buzz in Washington is the former - meaning bad news for Rove - though Rove's minions are spinning it the other way (not that they're known for being truthtellers).

As evidence we have:

The source said Rove, a powerful and controversial political strategist, was asked to testify by special prosecutor Patrick Fitzgerald, that he would appear voluntarily and that he had not been subpoenaed.

and:

According to NBC News’ David Shuster, legal sources say Rove volunteered to testify and was no subpoenaed. Rove’s decision followed a recent conversation with Fitzgerald.

The first source is a Rover. The second description is somewhat ambiguous, but leans more towards bad news for Karl.