NHL Uniforms put out a great post about many teams getting rid of their alternate jerseys, namely the Edmonton Oilers, Buffalo Sabres, and Florida Panthers-- as well as the lack of possible announcement of any new alternate jerseys coming to the forefront.
More over, the fact that many of the alternate jerseys have gotten so popular or bought more often-- they have been moved from alternate to the regular home jersery. In fact, the Los Angeles Kings, Dallas Stars, New York Islanders Philadelphia Flyers, Sabres, and Oilers have recently had their alternates move to their full-time home jerseys. Many thought the Nashville Predators were supposed to make their old alternate jerseys into the full-time look before they went with a full-gold presence. Also, the Anaheim Ducks seem to be rolling out their alternate more and more; that could get a road counterpart in the next few years.
However, the history of the third jersey is pretty interesting to say the least. The first instance of an alternate jersey was the 1955-56 season when the Boston Bruins used their white, black, and gold motif. They used that for two years, but would stop it in the 1957-58 season, only to bring it back for the 1959-60 season and have it last until the 1964-65 season. They were the only team in that era to use three jerseys in their wardrobe.
The next recorded instance of an alternate is when the Toronto Maple Leafs introduce new home and road jerseys, but kept their old home jerseys as an alternate in the 1970-71 season. It was merely a transition from old to new, as they would go away the next season. It was another 11 seasons before there was another alternate jersey, when the 1981-82 Pittsburgh Penguins worked in a gold jersey to their repertoire, which would last for two seasons, before the gold jersey became the home jersey in the 1983-84 season, lasting just one season, however.
Discounting the entire 75th Anniversary celebration by the NHL where the Original Six had alternate/retro jerseys for the 1991-92 season; the biggest boom and the start of the wide-spread third jersey craze was in the 1995-96 season with five teams kicking off the program (Mighty Ducks, Bruins, Canucks, Penguins, and Kings) and from that point on-- there was quite the boom for teams, as they saw how much of a great money maker it was....except the Blues.
Here's the breakdown of teams with an alternate jersey since that season, not including Winter/Heritage Classic jerseys-- unless they use it past their Winter/Heritage Classic year:
2007-08: 0-- New Reebok Edge design
Most Seasons With Alternate Jersey: 23, Boston Bruins.
Teams With Never Having An Alternate Jerseys: Detroit Red Wings, New Jersey Devils
While Greenstein has a point that it's interesting some alternates may be getting less and less prominent and some could be taken out of full rotation while others are being put into it-- the debate on whether or not they are going away is going to be there. They still are something people will clamor to have, and while some will be put into full rotation-- it just gives the team another reason to make another jersey in order to make even more money through merchandising. Plus, as well have seen in the past-- even the bad alternate jerseys are looked back at fondly, as we've seen with the Wild Wing and Burger King jerseys.
Even if they're going away, the fact more people than not will buy the new jerseys regardless of their look is going to be something teams remember and exploit (to a point) when trying to market them to not only their own fan-base, but the jersey collectors alike.