My two cents:
1. The loss of continuity- not just between the design of 3e and 4e, but between the people responsible for the two editions and the huge change of direction regarding the OGL- seems to emerge as a significant theme. It may just be coincidence that Gary Gygax passed away during the same period- certainly, he hadn't had direct control over the game or its direction in many years- but it does seem to indicate that a sort of 'changing of the guard' has taken place in the industry, and that some of the continuity that comes from having everyone be on the same page and having started from a similar place may have gone with him.
1. The loss of continuity- not just between the design of 3e and 4e, but between the people responsible for the two editions and the huge change of direction regarding the OGL- seems to emerge as a significant theme. It may just be coincidence that Gary Gygax passed away during the same period- certainly, he hadn't had direct control over the game or its direction in many years- but it does seem to indicate that a sort of 'changing of the guard' has taken place in the industry, and that some of the continuity that comes from having everyone be on the same page and having started from a similar place may have gone with him.
2. The release of 3e under the OGL may well emerge as the most significant act in the history of D&D since Gygax and Arneson released 1e. The OGL essentially let the genie out of the bottle, and it isn't going back- the core features of the most popular system in history are out there for the world to use, and for the last 10+ years the sort of homemade rules and monsters that everyone had been making for decades became not just a fun part of the hobby, but a potential business sideline. In the end, the OGL may be what undoes the D&D trademark as a tabletop RPG brand, while the underlying game lives on.
3. Lurking beneath all of this is profound uncertainty about the hand of Hasbro in the future of D&D. Anyone who glances at Hasbro's corporate filings will notice that D&D really never garners a mention- WoTC seems to be small potatoes in the Hasbro world, outside the occasional mention of Magic. Hasbro could easily decide that D&D is more valuable as a licenseable property (for movies, video games, board games, toys, and miniatures) than it is as a niche RPG product.