I've read a lot of takes and comments on this Wednesday's Lost out in blogland, and there seem to be two theories:
That this was a course correction instated by the writers after they realized how much the fans hated, hated, HATED! Nikki and Paulo.
That this was, more or less, the plan all along.
I'm in the latter camp. I think the intent was from the beginning to take a little time this year to see what the other survivors (and I haven't dome the math - how many are we down to now?) have been doing, and to do so by focusing on one pair, integrating them lightly into the early eps, and then indulging in one meta-bomb of an episode in which we saw how they had been interacting all long. As others have pointed out, too many elements from earlier episodes (Paolo using the toilet in the station, Paolo acting fishy when Nicki wanted to go there) fit too neatly with this episode to have been reverse engineered in.
But the most common complaint I'm reading, regardless of which school of thought is ascribed to, is that the episode was a waste, in that it didn't move the story forward at all. And every time I read a sentiment like that I can't help but marvel. A waste? I laughed more at this episode than maybe any other Lost episode to date. The meta references, the seamless incorporation of Nikki, Paolo, and Arst into earlier footage (especially the crash), the twisty nature of the story, the delicious reveal of why we were getting such specific time tags when we realized that "eight hours earlier" meant that the paralysis was about to wear off--I was highly entertained!
And let's face it - the show will run for at least four seasons, probably five. And with 100+ episodes to fill I really don't think every one can move the ball of the overall plot forward. No, too many of these would not be appropriate to the tone of the show, but two or three a season? That works for me.