If I could add say 2 hours extra into the day then we'd be able to play more and see these things, so far though at level 4 I've yet to see a quest which can't be done. Some need more planning than others but it's still fun, even jumping into lava twice in a row can be fun if your with people that see the funny side as well
Randomisation will help, both with the replayabliting of the quests that have it (when it does come in I imagine it will be for quests from that point, not the existing one's) but as I play so little I don't suffer the problem or replaying missions or being bored of it. DDO though certainly doesn't suit someone that wants the same kind of massive time sink other MMO's offer, content is finite and I'm much happier with the content in DDO than I've seen in other MMO's, and "high-end" stuff just ends up being more like a job than anything else.
And I still say grease will be next
People will adapt, grease on floor, heavy repeating x-bows, and maybe even rangers becoming popular.