From spiralknights.com

Greetings! I've got another update from Spiral HQ with some of what we're working on right now. As always the following is by no means everything that's in development and there's no ETA on any of this just yet.

Mission System!
A major addition is on the way that adds a new mission system to Spiral Knights, complete with a main campaign that allows Knights to play through, rank up and receive rewards. Missions are selected from an all new interface and are available to every player. Missions within the main campaign that require you to journey into the Clockworks will have the same elevator costs as the arcade.

I can't share too much at this point, but one of the missions in development will have Knights confronting one of the Crimson Order in a fortified castle filled with all manners of gremlin weaponry.

We're very excited about this new feature and will be sharing more information when it's available.

Year of the Dragon
A promotion will soon take flight to celebrate the Year of the Dragon!

Item Balance
Some item balance changes are on the way. Specifically this will target items that require tweaks to have their stats stand apart from similar ones and some changes to handguns to make them more varied and viable in combat. Check the forums for notice of these changes before they happen.

That's all I can share for now, keep your eyes on the testing forum for times when the test server will be made available!