Even though the record has only been out for a few weeks, Panic! At the Disco has apparently begun work on the follow up already. Chief songwriter Ryan Ross spoke to Billboard saying:

We’ve written a bunch of songs since [the release and] we’ve probably got about nine or 10 new songs going right now, so I hope that after our tour and all that, we can do another record. [The new material] is picking up where we left off. Because Pretty. Odd. was a lot different for a lot of reasons, I think we’re kind of finding something we’re drawn to, and the stuff so far definitely sounds harder to place to me. I’m not really exactly sure what it sounds like — I guess sometimes that’s a good thing.

The band is currently promoting their latest album on the Honda Civic Tour.
Source Even though the record has only been out for a few weeks, Panic! At the Disco has apparently begun work on the follow up already. Chief songwriter Ryan Ross spoke to Billboard saying:

We’ve written a bunch of songs since [the release and] we’ve probably got about nine or 10 new songs going right now, so I hope that after our tour and all that, we can do another record. [The new material] is picking up where we left off. Because Pretty. Odd. was a lot different for a lot of reasons, I think we’re kind of finding something we’re drawn to, and the stuff so far definitely sounds harder to place to me. I’m not really exactly sure what it sounds like — I guess sometimes that’s a good thing.

The band is currently promoting their latest album on the Honda Civic Tour.
Source