bishop, and has announced that this will be his "final full year" as Archbishop of Los Angeles. Whispers in the Loggia has the scoop (unsurprisingly), although American Papist has really been on the ball with this one.
For those of you unfamiliar, a coadjutor bishop is someone appointed to (a) assist the bishop of the diocese, and (b) take over as bishop once the bishop retires. In other words, Mahony has asked the Vatican to give him a "helper" bishop (which is what coadjutor literally means).
I see two ways of looking at this:
The Pessimistic View: Cardinal Mahony, perhaps the most powerful dissenting American Catholic, reaches mandatory retirement age in February 2011. The pope can accept his resignation at any time after that: all bishops over the age of 75 serve entirely at the pope's discretion. Had Mahony done nothing, the chair would likely have become empty shortly after his 75th birthday, and the Vatican (which seems to be trending towards very good episcopal appointments lately) would have filled it. But now, Cardinal Mahony has asked for a coadjutor bishop. Because the two will be working together for a year, the new bishop is less likely to be a radical departure from Cardinal Mahony himself. For the same reason, it's polite to allow a bishop pretty broad say over the choice of coadjutor bishop. The best parallel I can come up with is political: as president, Bush wasn't allowed to choose his successor (Obama), but he was allowed to choose his Vice President (Cheney). Had he died in office, the VP would have automatically taken over. By asking for a "VP," so to speak, Mahony may realistically be trying to pick his own successor. Indeed, in this case, it's believed that the nuncio will run the terna (the top three list of candidates) past Cdl. Mahony for approval before submitting it to the Congregation for Bishops. The final decision, of course, will rest with Pope Benedict, and if all three choices are bad, he can always request a new terna.
Beyond the fact that Mahony has found a way to get involved in choosing his own successor, there's another potentially unpleasant element. No matter who gets chosen, he'll be #2 to Mahony until Mahony steps down, giving the Cardinal as much as a year to impart his unique views and episcopal governance style even on an otherwise good bishop.
The Optimistic View: The Vatican has done a great job recently (thanks in large part, I imagine, to the papal nuncio, Archbishop Pietro Sambi) in promoting orthodox, humble, likeable men. Take, for example, the decision in 2008 to make Archbishop Daniel DiNardo of Galveston-Houston a Cardinal, which Whispers in the Loggia described as catapulting "the Curialist who picked parish ministry over a Vatican post from his founding pastorate in suburban Pittsburgh to an elector's seat in the conclave." Or the appointment of Abp. Dolan in New York, famed for his "orthodoxy with a light touch." And with the selection of the doctrinally-solid Abp. Burke and Cdl. Cañizares to the Congregation for Bishops, this is trend likely to continue or improve.
It's not at all unlikely that Abp. Sambi can find some quality candidates to compose his terna. Since Cdl. Mahony will almost certainly step down (or have his mandatory resignation letter accepted, anyways) near his 75th birthday, he's not likely to liberally use his veto. The process of finding good bishops is a slow one. If he nixes all three of Abp. Sambi's choices, he might not be around to even approve of the next list.
So it seems quite possible that a high-quality candidate can still make it easily-enough onto the terna. An orthodox, hard-to-dislike coadjutor with an outgoing personality would be a much needed voice in the Archdiocese, and the sooner he's installed, the better. By having him serve as coadjutor at Mahony's request, he's less likely to be seen as the embodiment of a Vatican crack-down. Particularly if he's likeable, this could make for a very smooth transition, and could actually serve the purpose of restoring orthodoxy to LA better than had the Vatican come in with a heavy hand upon Mahony's departure.
My personal guess: I fear the first possibility, hope and pray for the second, and guess that the final choice will be a sort of uninspiring but orthodox bishop. Somebody who isn't personally heretical, but doesn't make too many waves in rooting heresy out: someone who will slowly reform the Archdiocese. Frankly, that wouldn't be a terrible outcome: a sort of Archbishop Wuerl figure. Any guesses from anyone else?