The fourth beta event for Guild Wars 2: End of Dragons is happening next week. You'll be able to play test all nine elite specializations, and hop aboard the two-person tank that is the new Siege Turtle mount.
The beta is open to all players, and there will be beta test slots available at character select. Beta test characters will be level 80, already having the elite specialization and appropriate build for the class you chose and already equipped with suitable gear. With the event running from November 30th through December 4th, should you choose to, you'll be able to test all of the new specializations, possibly ahead of your decision if you're planning on playing the expansion content. Beta characters can go into any existing content in Tyria that you’ve unlocked. This includes World versus World, player-vs-player, instances, and more.
The Siege Turtle is quite the mount. Not only is it a giant combat mount, you can fight while still on it, a friend can also get on board your moving tank. Your turtle can be used more like a vehicle that you drive, one that happens to also come with jump jets. Have fun with power from above as you slam into enemies. Having a gigantic turtle, solidly built, and designed for combat on your enemies just might turn the tide for you. You'll be able to get a feel for just how this new mount works and whether or not you're looking to turn this giant turtle tank into one of your tools.
With the release of End of Dragons coming in February, the beta events have expanded and offer more to try. For the full event information, see the announcement over on Guild Wars 2.