Live at E3: Turbine’s Dungeons & Dragons Online: Stormwatch Hands On - it sounds fairly positive, and it also seems like they're taking a sort-of-similar approach to Guild Wars with regards to levelling:
The main idea behind DDO is to “remove the grind,” something you hear a lot from the creators of massively-multiplayer RPGs these days. Turbine’s trick is remove experience point gains from killing monsters entirely, instead rewarding players for completing mission goals and dungeons (although sometimes those goals include killing boss monsters, of course). It’s a promising idea, but I also got the impression that it might make it easier for walkthroughs to affect the rate of leveling for power players.
While I like the idea of removing the grind, I think there's a happy mid ground. SWG was basically designed (talking post CU here, although some of this may be true now also) so that you couldn't really "play" until your grind was finished. This was true of combat chars where the master box gave you bonuses that you couldn't do without (ignore stacking professions here), and also of crafting chars where no one would buy anything not crafted by a master because the stats simply didn't compare.
It was similar in DAoC pvp - you could take your level 40-45 character into the pvp areas and constantly get creamed by groups of full level 50's who you were hard pressed to even scratch (although I realise they did modify that at some point, but I was well gone by then), so you were forced to finish your grind before you could start to enjoy pvp.
I've played a couple of other games which simply aren't like that. Legend of Mir (2) was one where you could participate in guild hunts and pvp pretty quickly, and then level when there was nothing going on. LoM was also unique in that the grind got so steep in the end that you could never reach a max level - once you got above level 40 things were so slow that you just ticked up and didn't think about levels so much. I kind of liked that.