This event has been described as very difficult multiple times by CG. The only other events that have been described as very difficult were Chewbacca and the Galactic Bounty Nest events. Carrie mentioned on Twitter that it should be pretty close to those events. One thing to keep in mind is that this is a Journey event which means each round may use a different set of characters. Don't depend on just a couple characters being able to carry you. If you want to wait and see that is fine, but have the gear ready.
Darth Revan event is confirmed to start on Monday March 25th. The event will start immediately following a content update at 11:00 AM Pacific time. This will be the first time an event start immediately. [Link]
Darth Revan event (Scourge of the Old Republic) will likely start on March 21st, however it's possible it could start later if there are issues with it going live that day [Link]
Darth Revan has finally been announced. Sounds like it will be a Journey event and requires Bastila Shan (Fallen), Canderous Ordo, Carth Onasi, HK-47, and Juhani. [Link]