Apparently they're writing the third movie in the thematic 'Cornetto' trilogy, THE WORLD ENDS, right now, which will do for disaster movies what SHAUN did for zombies and HOT FUZZ did for cop movies.

The reason it's taking so long is that they've been insanely busy, with Simon Pegg spending last year and this working on the TINTIN movies for Spielberg and Jackson. They've had to wait until they had some free time to do the new film, although I wish they'd made it more of a priority.