
I adore IC dungeon runs, and we do them at least once a week in my FC (sometimes with friends from XI:7). The timer is an issue, as Ildur points out, so our usual strategy is to hold the RP to some introductory RP to set the scene outside the dungeon or in a channel, a little bit of chatter at the beginning, witty repartee or short commentary in the midst of the trash, and some brief conversations before and after bosses. The bulk of the RP, then, is before and after the dungeon itself. That said, we've found that, even with people at level and new to the dungeon, the time pressure is not especially brutal.
In terms of the setup, we have quite a few we use. One approach is to make the dungeon generic; for instance, it's not Halatali, it's some ruins under Thanalan. Another is to come up with a reasonable explanation for why the dungeon keeps getting repopulated (the aethereal disturbances make it attractive for cultists; limited resources ensure breeding monsters continually repopulate; we're cleaning out a different part of a larger complex; the constant Dravanian onslaught results in the fortress being retaken; etc.). How we get people together is usually a function of "hey, I heard about this place I want to investigate" or "my Grand Company wants someone to look into this area." Sometimes it's tied to a larger plot, but not often.
EDIT: My advice for RPing while fighting through trash (or in boss fights) is to keep the comments short and not expect (or intend to create) a conversation. It makes sense IC, since your character is in the middle of battle and in a fairly dangerous situation, even if you don't create a justification IC for the timer. Random battle quips are how it came out, for instance, that L'yhta has a curious predilection for "gobbiespeak".
In terms of the setup, we have quite a few we use. One approach is to make the dungeon generic; for instance, it's not Halatali, it's some ruins under Thanalan. Another is to come up with a reasonable explanation for why the dungeon keeps getting repopulated (the aethereal disturbances make it attractive for cultists; limited resources ensure breeding monsters continually repopulate; we're cleaning out a different part of a larger complex; the constant Dravanian onslaught results in the fortress being retaken; etc.). How we get people together is usually a function of "hey, I heard about this place I want to investigate" or "my Grand Company wants someone to look into this area." Sometimes it's tied to a larger plot, but not often.
EDIT: My advice for RPing while fighting through trash (or in boss fights) is to keep the comments short and not expect (or intend to create) a conversation. It makes sense IC, since your character is in the middle of battle and in a fairly dangerous situation, even if you don't create a justification IC for the timer. Random battle quips are how it came out, for instance, that L'yhta has a curious predilection for "gobbiespeak".

The Freelance Wizard
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))