The Senate Judiciary Committee completed their confirmation hearings for the Roberts nomination today. They are expected to vote in committee on the nomination next Thursday, the 22nd. That will send it to the full Senate, which will likely begin deliberations on Monday the 26th and a final vote sometime that week. That should mean Roberts will be seated as Chief Justice by the traditional beginning of the new Supreme Court term on the first Monday in October. After the final vote on Roberts, you can expect the White House to nominate someone to fill the vacant associate justice position.
Will it be someone really to the right, in the mold of Scalia, or will Rove put up someone more along the "minority" lines of a woman or the Attorney General? Rove's record so far of picking competent people to fill positions is remarkable for its failures and not successes. Roberts maybe someone who sublimated his views to get confirmed and then treat us all to some pretty activist opinions, but he probably is competent and suited for the role. The odds of another are too slight to forecast.