Has anyone else noticed how popular Adventure Paths seem to have become? Not among fans, I mean, but it's like every other company is planning on putting one out for 4e.
Do you mean they are not popular among fans, but popular among companies, or just they may or may not be popular among fangs, but how they became popular among companies?
I didn't notice so far in particular. But maybe people are looking at Paizo and how Pathfinder creates a large fanbase and they think that might be the best way to go.
Who knows, maybe 4E, instead of having a "rules bloat", it will have an adventure bloat and everybody will eventually decry how nobody is creating character options any more.
Alternatively, they do it because people like to tell stories and telling them in the form of an adventure supplement might be particularly compelling for RPG players.
Personally, I like Adventure Path. They allow a coherent campaign without risking that a DM runs out of ideas or motivation for his own campaign. (A problem I sometimes experienced). They reduce the DMs workload a lot, too, so he might be better able to fleshing out character details.
Finally, they provide a common experience among players world-wide, and that's not bad, either.
The only disadvantage is that they tend to be a little more rail-roady then personalized campaigns where the DM can react to the player preferences.