While Rocco Palmo beat us to the punch in observing this, it's still worth noting here that this morning's appointment of Bishop Gregory Aymond of Austin Texas as Archbishop of New Orleans (congrats, Archbishop-designate Aymond!) gives the Archdiocese of New Orleans four living archbishops.
The other three being now-retired Archbishop Alfred Hughes (2002-2009, Archbishop Francis Schulte (1988-2002) and Archbishop Philip M. Hannan (1965-1988). As Rocco pointed out that this is unprecedented, all I have to add is hopefully somebody takes a picture.
While it's more-or-less equally common for a diocese to have either just an ordinary or one active ordinary and one retired ordinary, it's interesting to note that New Orleans was still in rare-enough territory before taking a turn into unprecedented.
It appears that, out of 195 dioceses and archdioceses, eight U.S. dioceses currently have three living ordinaries, that is, an active ordinary and two living emeritus bishops. This does not include auxiliary bishops, active or otherwise, nor does it count dioceses whose bishops have been assigned elsewhere and replaced.
That said, the eight are Amarillo, Kalamazoo, Marquette, Palm Beach, Providence, Sacramento, Springfield in Massachusetts, and Steubenville. (Research comes from the online Catholic hierarchy database, which is in no way affiliated with the USCCB.)
And since this blog has displayed an inordinate interest in the nationwide statistical breakdown of bishops (at least until next week's meeting is over), it's worth noting that the new numbers are:
Currently, 6 dioceses are vacant (sede vacante):
There are 425 active and retired Catholic bishops in the United States:
257 Active Bishops:
5 Cardinal Archbishops
1 Coadjutor Archbishop
154 Diocesan Bishops
0 Coadjutor Bishops
69 Auxiliary Bishops
168 Retired Bishops:
7 retired Cardinal Archbishops
21 retired Archbishops
91 retired Diocesan Bishops
49 retired Auxiliary Bishops