The history of our hobby can be divided into four phases. The first is the 1860-1910 period. This was the birth of philately, where collectors first began to acquire stamps. It was when the first catalogs and albums were developed as were the basic rules for quality and what is appropriate to put into collections (genuine vs reprints etc). The tools of our hobby (perf gauge, tongs and watermark tray were developed at this time too). The second period (1910-1950) was the period when collectors expanded the boundaries of the hobby in response to the increasing popularity of philately. First day Covers and plate blocks began to be collected and specialization became more common in response to the lack of enough scarcer world wide material to satisfy demand. The third period (1950-2000) consolidated the earlier phases of the hobby and expanded philately’s emphasis on mint stamps and especially newer issues. Stamp collecting became such a big business for Post Offices that new issues became common and increasingly, as the decades progressed, collectors could be philatelists and never buy anything but new mint stamps as they were issued.
The current phase that we are in, the fourth phase, began about the year 2000 and can be called the post modern phase of the hobby. This period began because of the Internet and is 
defined by it. Philately was an imperfect market. Dealing in the early days was very local in orientation. If you didn’t live in New York, London or Paris, where the few larger dealers had shops, you were out of luck in terms of getting a good chance at new material as it came to market. The ever increasing popularity of mail order, auctions and shows in the pre 2000 period made philately more transparent but the stamp market never became a truly integrated one. The Internet has changed all that. Virtually all stamps are now sold or listed for sale on the Internet and any collector with time, and the proper search engine, can find all of the specialty items in his area that are being offered.
International stamp market integration has produced two new collector reactions that are the major characteristics of our collecting period. First, collectors have become so used to seeing large numbers of rarer stamps for sale that some of the trigger impetus to buy is gone. When your local dealer got in one or two $5 Columbians a month and he had one and you wanted one, you bought it. Now collectors see such a quantity of the tougher stamps for sale that they can wait before buying, and such waiting can ultimately replace acquisition as part of the philatelic process. And second, the large amount of material constantly being offered for sale has made many collectors refine even further their specialties. I saw a collection last week of the compound perfs of the postage dues of Romania. This was a degree of philatelic arcana that would have satisfied the most philatelically obsessed of a generation ago. This collector, though, was so inundated with material in even this obscure field that he limited his collections to the proper perf types and insisted too on legible town cancels.
Where this will go is anyones guess. Looking back at the history of a hobby is easier than seeing clearly where the hobby is on the path that marks its evolution. And extrapolating from that line to predicting the future is even more difficult. My guess, and its just a guess, is that our hobby begins to bifurcate. Ultra specialists move off into ever minute specks of the hobby while pretty picture new issue collecting becomes the norm for most people who call themselves philatelists.