Whether you missed the last beta event, or you're just hankering for more after participating, you'll be happy to hear this news.
The next beta event -- also the first to make PvP available -- will be taking place this coming weekend from January 7 at 10AM PST to January 10 at 10AM PST. The event will introduce Warfronts, Rift's instanced player-versus-player content, which pits Defiant and Guardian players against each other in the map Black Garden.
Beyond that, all of the content from the first three events will be accessible, in addition to an increased level cap of 27. Players will also be able to access two new zones -- one for each faction -- in Gloamwood and Stonefield. More dungeons are open for the event, too: Darkening Deeps and Deepstrike Mines.
Be sure to stay tuned for further updates on the Rift beta and the game as it marches toward its release.