I *really* wanted DDO to win me over. It didn't.
The instanced dungeons, I've got to admit, are quite well done and a unique experience. After grabbing a good pickup group and completing a few dungeon crawls I started to find them really samey however... not a good sign after 3 hours play or so. Because absolutely every dungeon is instanced I never felt like I was playing a massively multiplayer game - just a multiplayer one. It was more like NWN than EQ2. Maybe that's not a bad thing, but it gave the game a feel totally different feel to the preconceived expectations I had formed.
The whole game just didn't seem to hang together in some intangible way. Graphically it reminded me a lot of AC2 - too much like AC2 actually, it seemed slightly dated. I'd describe the graphics engine as functional rather than breathtaking, but without the great art direction of Blizzard that allows WoW to have crappy low poly counts and get away with it.
A more serious problem was the complete lack of atmosphere. Partly this is due to the setting of Eberron (Dear Wizards of the Coast... why, oh why, oh why did you not allow Turbine to use the Forgotten Realms? Yours angrily, Elminster), but the majority of fault lies with the way there is bugger all to do outside of bashing dungeons. No crafting, no housing to decorate, no fluffy little sub games, collection quests or any other manner of totally useless nonsense that makes these games fun. Players crowd into Inns to recuperate after dungeons because that's what the designers have decided they need to do. Great! I love inns - alll the best D&D adventures in my own friends' games started in inns. The problem is that there is nothing whatsoever to do in the inns once there. Nothing! 90% of the players present in inns are blatantly afk doing something more enjoyable like making a cup of tea, drooling on their keyboards or perhaps knitting. Once their characters' bars are back to full it's back to doing the only activity the game allows - attempting an instanced dungeon.
If designers are going to force people to congregate in shared spaces such as inns then give them something to do. SWG had hospitals where various medic classes could perform healing, training and medical supplies. Even the cantinas featured groups of entertainers that would heal you (okay they were nearly all macro bots... but at least the designers tried!). Age of Conan is going to allow you to get drunk and then kick off a mass drunken brawl in inns. I really don't understand what the designers hoped to achieve by their decision to provide absolutely no content other than the dungeons. The only effect I could see was to make people treat the game like an updated version of Diablo - hardly the right environment for roleplaying.
Other things that irked me were the tedious number of zones and loading screens that you have to sit through when simply running through town (enter the inn *loading*, go to the weapons shop *loading*, visit an NPCs house to pick up a quest *loading*) and the setting. I cannot for the life of me fathom why the decision was made to allow players to play giant robots when half of the "classic" D&D races are missing. Playing EQ, UO or DAoC felt closer to a typical D&D setting than DDO. How bonkers is that? No doubt Turbine or WoTC would argue that they went for a "new" and "exciting" seting but that isn't what most people want from D&D - they want classic fantasy and all it's loveable cliches.
On the plus side I really liked the combat. It delivered what it promised and offers more tactics than any MMO I've played. Fighters can actually form a shield wall and physically block enemies from getting at the weaker casters. You get the correct bonuses for attacking from the flanks or rear so you find yourself constantly repositioning in relation to your enemies (especially if you're a thief!). Climbing, swimming, secret doors, traps and morale failure rules all feature and add a new dimension to play.
*sigh*
If they scrapped the setting, made the world more expansive and packed in some other activites it would be a pretty good game. As it stands Turbine have dropped the ball big time IMO and wasted a golden license.