Solicitor General Paul Clement is reported to be President Bush's choice for acting Attorney General.
Update: The AP is also reporting that a permanent replacement for Gonzales may not be announced before the President leaves for Australia next Monday, which at least suggests that the White House does plan on sending a nomination to the Senate for confirmation, rather than attempting some sort of recess appointment or other vacancy shenanigan.
Late Update: As U.S. News' "Washington Whispers" first reported over the weekend, DHS Secretary Michael Chertoff is being floated as a possible permanent replacement for Gonzales. CNN is now reporting that Chertoff is the "likely" nominee. Considering that Chertoff presided over the Katrina disaster, his nomination as attorney general would be nothing short of unbelievable.