There's a small slice of the MMORPG community that DDO will appeal to, but for the rest of us it's SWG all over again.
On the other hand, and D&D player will tell you the adventure you play is as only as good as the DM running it, and the computer is a lousy, lousy DM. It makes up for a total lack of imagination and flexibility by offering loot galore, the old "Monty Haul" style of play. Repetition of the same quests over and over again only makes the computer's faults even more glaring. It's like finally finding the perfect group of people to game with, only to find your DM is an intractible jerk...and you're stuck with him.
To make the problem even WORSE, there are plenty of bugs and quest balance issues (as of this writing, two popular quests had already been pulled for "readjustment" as players were finding exploits). Since the only way to gain experience is to complete quests, bugs that prevent you from doing that mean you're just wasting your time while inside. Nothing's more frustrating than to have to repeat a tough multi-part quest because A) You didn't get credit for one part due to a bug, B) You don't get credit for the entire quest meaning no reward at the end and C) You're out experience and time wasted.
I don't think DDO is going to make it. There's no PvP, no crafting, no explorable world, no quick farming for a few hundred XP to make a level. Yes, what DDO does have can be a lot of fun, but in the future I forsee FFXI's brutal "two hours waiting for a party" disease.SWG's ongoing slow and painful death is pretty bad to watch, but not only do I believe DDO is going to fold, I think it will do so almost frighteningly quickly. There's already plenty of folks who are level 10 rank 4 (the level cap) and right now the only thing to do for them is to start a new character.
As somebody who's been on both sides of the DM screen, I can tell you that a good DM is just as important to a campaign as the players are, maybe even a bit more so. The DM's job is to make it work. Look at how successful the Neverwinter Nights series has been, especially with the multiplayer DM experience. DDO on the other hand is without the usual MMORPG time sinks like crafting or even the ability to solo, the quest is the thing. Since there's nothing there to hold the usual MMOkids attention and the narrow niche audience of the game isn't going to tolerate going through the same quests with yet another character.
Turbine has promised more content and has promised it quickly. But from what I've seen of DDO, I don't think they'll be able to deliver it as quickly as is going to be required without the game turning into one huge beta test. Combined with the decidedly niche appeal of the audience, we're going to see mass defections by this summer.
Don't get me wrong, there's a lot of potential here. But this game needed another year in the shop and another 10 levels of content before being released to the public. The bottom line: unless Turbine delivers a *bunch* of new content quickly, puts in player crafting, and seriously considers some sort of PvP activity (even if it's a group player activity like FF XI's Ballista sport) the next time you see mention of this game from Gamespot will be on the list of "Biggest Disappointments of 2006" voting list or the inevitable "The Five Biggest MMORPG Flops: What Went Wrong?" article.