Heart of Fear is the upcoming content installment for EverQuest! It will consist of 3 zones (The Threshold, The Rebirth, and The Epicenter). The content will be free to those who have purchased the Rain of Fear expansion.

In the Heart of Fear content release, every class will be able to obtain powerful class specific weapons. There are two versions of the weapons: Group, and Raid. These weapons are obtained through the Achievement system. It's still unclear exactly what all is involved to obtain them, but we do know it will require the completion of ALL RoF group missions. You can preview your classes weapon by clicking one of the class links on the menu.

Here is a quote from Phathom on the topic:

Quote: Phathom, Heart of Fear Beta
"It's time. The desperate battles, relentless hunts, and cutthroat dealings of the past year have all been working up to this moment: the final confrontation with Cazic-Thule's terrifying power. The god of fear is dead, but brave adventurers must enter the final reservoir of his lingering power on Norrath, the Heart of Fear, to conquer its evil once and for all. But brave adventurers are not alone in their quest—a myriad of monsters both familiar and new inhabit the Heart of Fear, hoping to steal Cazic-Thule's power for themselves and ascend to become Norrath's new god of fear. Can you stop them all in time? Can you even find them? A betrayer in your midst is eager to teach you the new meaning of fear. Prepare yourself."