"Dungeons & Dragons Online" has had a rather volatile history. It came out to much fanfare, hyped as the first MMORPG that would really capture the tabletop roleplaying experience... and once that hype was exposed for what it really was - just a bunch of marketing blather - the game took a nosedive. Things got so bad that it was about to close outright, but in a last-ditch effort to save the game, Turbine decided to take the game to a hybrid free-to-play payment model.
And just as quickly as DDO fell, it shot back to life and became a huge hit! Free-to-Play saved the game, and suddenly DDO was making so much money that Turbine decided to take their flagship game (Lord of the Rings Online) to a hybrid free-to-play model just a year later. Things have leveled off some with "Dungeons & Dragons Online" in the years since, but it is reportedly still making good money for Turbine.
... but that is going to end, sooner than Turbine would certainly have hoped.
You see, at the end of 2012 Cryptic will be releasing "Neverwinter", a no-subscription MMORPG based off of the smash hit D&D-based video game "Neverwinter Nights". While DDO has succeeded as a free-to-play game, it has also succeeeded partially because it was the only D&D-based MMO on the market. But in a little less than a year, "Neverwinter" will take away that advantage from DDO. Futhermore, being NW uses its own form of free-to-play, DDO won't have that advantage, either. The only things DDO will have left going for it will be that it has been around for several years (lots of built-up content), and their unique setting (Eberron).
Oh, wait... NW comes with a modified version of the Foundry system used in "Star Trek Online", so players will be able to create lots of content to share with the rest of the playerbase. That will quickly help NW build up some additional content, albeit player-made, but content just the same. Also, NW uses the Forgotten Realms D&D setting, which is much more popular than Eberron, a setting Wizards of the Coast basically forced Turbine to use for DDO, since nobody was really into it.
So what does that leave DDO? Not much. But some would say that Cryptic will screw up with "Neverwinter", that they can't run a proper MMORPG anymore (see previous 'failures' in "Champions Online" and "Star Trek Online"), and as such NW won't threaten DDO at all. And you know what, they could be right. But at the same time, even if NW doesn't strip DDO of the vast majority of its players, leaving it a broken husk of a game, there's this other little MMO coming down the pike in a few years: Pathfinder Online. PO is based off of the very popular tabletop RPG "Pathfinder", which uses similar rules to D&D. While PO is coming from a small development house, if it does well at all, DDO and NW both have something to fear.
In short, "Dungeons & Dragons Online" has been like a wounded surfer in shark-infested waters for several years now, and for the last couple of years has managed to bandage their wounds and start paddling towards shore. But the wounds have continued to bleed, and a couple of Great Whites are circling DDO, waiting until they can move in for the kill.
Subject: all my own work 
