The Towny world will reset November 27th. This is unavoidable due to several previous updates, bugs, and exploits all culminating in an unstable world. To make it up to you, I've implemented a system that will allow you to keep a limited number of items you believe are important. Here's how:
When you open your enderchest by right-clicking it (there's 2 at spawn if you need them), you'll find you've accessed your "PandaSafe". This is where you can store the items you wish to keep. I recommend storing any case items, keys, and things you believe are valuable that you don't want to lose. Your PandaSafe has 27 slots to store items in. If you need to access your regular enderchest, simply run the command, "/echest" and it will open on your screen. This command is available to all players until 7 days after the reset. After the reset, you'll have 7 days to remove your items from your PandaSafe before the PandaSafes are reverted back into your regular enderchests.

You'll find the new world, after the reset, to be much more exciting. There will be custom terrain, biomes, and structures to be found everywhere. I've decided to abandon the idea of a complicated PvP system and instead stick with something basic. PvP will be enabled and players with God mode or Fly will have their god/fly disabled if they attack a player. Attacking a player will "tag" you for PvP for 10 seconds. Logging out while tagged will kill you and fine you ¥100; this is to prevent unfair PvP-logging. Flag war will be enabled at all times and regular war will be enabled on the weekends. War only applies to nations and towns in nations. You can opt-out of war by either not joining a nation or paying the nation neutrality fee.

Creating a town is now free. You must claim land before you can build/break on it. If you need to gather resources, ie - via mining, you can build a portal to the mining world, TheUnderground. PvP is enabled in TheUnderground, so be careful. Once there, you can mine to your heart's content. You can find various blocks normally difficult to obtain and even entire mining structures with chests full of loot.

Lastly, each night has a small chance of triggering a Bloodmoon. During a Bloodmoon, monsters are tougher, more prominent, and won't go away until at least a little over a dozen are killed.

For more detailed information on the above changes and other changes I've made, visit the Towny Changes post here:

Update: To clarify, only the items in your PandaSafe will survive the reset. Any items in your inventory or enderchest will be removed. Balances will be reset, though rank holders will start with their respective rank balances. Your rank benefits will still be available after the reset.