. . . Was their ever any official change in naming procedures? From what I recall, in the years before and including WWII, naming ships was fairly straightforward: battleships were named after states, aircraft carriers named after battles, cruisers named after cities, and destroyers named after persons.
I'm not certain that the conventions have ever been officially codified. Congress has the power to name any ship for which funds are appropriated (by specifying the name in the appropriations bill), but this prerogative is practically never exercised. Since the US Navy began assigning ships hull numbers near the end of the 19th century, there have been numerous exceptions to and anomalies in the naming conventions, and occasional major revisions.
For example, every battleship ever laid down has been named for a US state--with one exception. During the American Civil War, the screw sloop USS
Kearsarge became famous for sinking the notorious Confederate raider
Alabama. In 1894
Kearsarge was wrecked on a reef, and attempts to salvage her proved unsuccessful. Congress therefore directed that Battleship 5 (later BB-5) should be named for her.
Cruisers were always named for American cities, except that one war-construction cruiser was renamed
Canberra in honor of HMAS
Canberra, which was sunk along with four US Navy cruisers at the Battle of Savo Island. (I've seen a joke that says she should have been named USS
Oops! Sorry! because
Canberra was sunk by US torpedoes, but this allegation is unproven.)
Aircraft carrier names have always been a mixed bag. CV-1, a converted collier, was named
Langley in honor of an American aviation pioneer. CV-2 and CV-3 were originally laid down as battlecruisers, and after conversion they retained their names
Lexington and
Saratoga, respectively. (Oddly enough, the four scrapped battlecruisers were not to have been named for battles; rather for famous American warships from the age of fighting sail). For some reason, the decision was taken to continue the sailing-ship name tradition, resulting in
Ranger,
Enterprise,
Wasp, and
Hornet.
Yorktown for some reason followed the American Revolutionary war battle convention.
During World War II, in addition to those named for previously lost carriers, both the battle (
Bunker Hill,
Antietam,
Cowpens, and pre-steam (
Essex, Bonhomme Richard,
Intrepid) conventions were used, plus the Founding Father (
Franklin,
Hancock) convention was added. And one CVL was named the
Wright (presumably to make up for the slight delivered in the naming of CV-1
) Finally, one carrier was named
Shangri-La, after the fictional Asian mountain paradise in the novel
Lost Horizon, after FDR joked that Doolittle's Tokyo raid had been launched from there.
Upon the death of FDR, one of the new Midway class supercarriers was named in his honor. The next class of carriers was named for Secretary of the Navy (later Secretary of Defense) James Forrestal, who committed suicide while in office (presumably due to the stress of political infighting and of unifying the armed forces). Other postwar carriers included
Ranger, Saratoga, and
Enterprise (honoring their WWII namesakes),
America,
Kittyhawk (really making it up to the Wright Brothers
), and
Constellation (fighting sail). The last pre-
Nimitz class carrier, a modified
Kittyhawk class, was named in honor of John F. Kennedy.
The first major convention change was naming ballistic-missile submarines for famous Americans (and honorary Americans). After all battleships were retired from active service, first nuclear-powered guided-missile cruisers, and then ballistic-missile submarines, began to be named for states. The
Los Angeles class attack submarine broke the longstanding convention of naming submarines after marine life. Admiral Hyman Rickover is alleged to have given the reason for this as "Fish don't vote." Finally, cruisers are now being named for battles, rather than cities or states.
I feel like Tom Cruise when Stan says he's just an "okay" actor. 
I'm going to stay in this closet, and I'm not coming out--not ever. 
