PotC was a summer release last time, correct? and we did get a mini update in the form of the Black Pearl (which I have very little interest in acquiring) so it could get a few more sets if it sold well.
There are also some characters missing, like the Governor AND skeleton pirates from the Black Pearl so there should be other sets TLG cold come up with.
There are also additional pirates movies in the works, so since LEGO already has the license for the movies, if the sets did well, I would think they would continue.
On the other hand, we haven't really heard anything about the theme continuing at all, and throwing Davy Jones in the Black Pearl set did seem like a way to get him out there. (Then again, my feelings on the Pearl are he might be the ONLY reason to get it, and maybe LEGO knew that!)
I think we need more people to chime in here... expect this discussion to get a blog entry soon
Actually, I believe PotC was a May release. In other words, it was somewhere between winter and summer waves.
And I think that the theme may go on hiatus even if other movies are in the works. There haven't even been any trailers for the next one yet, which means it could very easily be one or two more years before the fifth movie hits theaters. And that's a long time for a license which, from my experience, doesn't sell a lot of toys except when new movies are out or at least on the horizon.