This week's Steam Marketing message outlines the changes planned for the Pyro class in Team Fortress 2 in an upcoming update:

We've almost completely wrapped up the next big release for Team Fortress 2, which will focus on the Pyro class, along with the Meet the Sniper movie. We've spent time looking at how the recent Medic release went, and have rolled feedback from that release into the new item designs for the Pyro and into the design of the achievements required to unlock those items. One item, shown here in concept form, will be the Axtinguisher. Although it does about half of normal damage to standard run-of-the-mill non-burning enemies, once you light someone on fire the Axtinguisher will guarantee a critical hit.

Along with all of the new content, we're also going to be making some significant changes to the Pyro class for everyone, regardless of whether they have unlocked any new items.