As a former Lostie, and someone who actively engaged in the online game and who has purchased Dharma Initiative merchandise in the past: I LOLd.
In the main plot, Jimbo Jones (the bully with the skull printed on his t-shirt) insists that Bart chaperone his girlfriend. As if Bart, who as he points out is comfortably pre-adolescent, is tantamount to a eunuch. Bart is nervous and annoyed at being strong-armed into this time-consuming, unpaid, and (so he thinks) boring assignment against his will. Then he (predictably) gets a crush on Jimbo's girlfriend, and it all goes haywire.
In the secondary plot, Homer gets hooked on "Lost," or rather, on a parody of "Lost" which the show calls "Stranded." As a former Lostie, and someone who actively engaged in the online game and who has purchased Dharma Initiative merchandise in the past: I LOLd.
There are actually two main jokes with this sub-plot: one is that "Lost" was a silly show with silly obsessive fans (guilty as charged). The second is about people who watch a show five years behind, and insist on NO SPOILERS even though they also insist on talking about it with you.
As someone who has been on both sides of both of these equations, I felt like the jokes hit home pretty hard. I'm not sure if I could call it a success, though, because it's so "inside baseball" that I imagine anyone outside that fairly small sub-set of humanity would be left feeling very shruggo about the whole thing. If you're not going to at least smile at the sight of a bunch of baffled island castaways standing in front of a rock wall with a giant crank sticking out of it, then this probably wasn't the episode for you.
I had more mixed feelings about the main story. In one of the pivotal moments, Jimbo's girlfriend "repays" Bart's kindness by flashing him her boobs. I was glad that the show spun this such that Bart was extremely disturbed by the event. I mean, what if some sixteen year old guy had shown Lisa his wiener? We'd be pretty freaked out by that, wouldn't we? That whole thing was so upsetting to me (and apparently to Bart as well) that I wish they would have cut it in favor of, I don't know, a peck on the cheek or something.
Mad props to this week's couch gag by Bill Plympton, by the way! It really must be seen to be believed.