The Rift site has been updated with a forward look at the next Starfall Prophecy update coming on March 1st. Called Forged in Flame, the 4.1 update will feature a new 10-player raid called the Tartartic Depths and with new Eternal weapons that can be improved via a questline that sends players off to close rifts, complete jumping puzzles and defeating a variety of enemies. These Eternal weapons will be considered "best in slot".
Clerics, Mages, Warriors and Primalists will gain a 2-handed Eternal weapon, while Rogues will earn two one-handed Eternal weapons. On very rare occasions, Eternal armor pieces and additional weapons will also drop in Telara, and can be improved through the Active Upgrade system.
Read up on the details on the Rift site.