From the publisher's web site:
This is a playtest release of more than 140 NPCs and monsters of the Trembling Plains, including that region's unique Spirits of the Land. FFN also provides adventure leads, equiptment, feats, prestige classes, and other new material for running a campaign in the Trembling Plains region. FFN is the companion book for Lost Cities of the Trembling Plains, which is back in production and will be released in beta form by the end of 2007. The final version of FFN may include NPCs and monsters from other future releases related to the Trembling Plains, such as Prison-State of Eldaarich, City-State of Kurn, Flamesky, and Silt Sailors of the Kulag Fleet. Please submit playtesting feedback to templarate at lists.athas.org.