It's great to see the interest in this forum for a Saga Age Iceland setting for BRP! For a long time I wished someone would write a fantasy setting based in Iceland of the Viking period, and I'm very excited to be now writing that setting myself. I have been working on the project for several months now, spending a lot of time in the National Library of Iceland, here in Reykjavik, researching the history and myths of the period, and the writing of the book is coming along nicely.
The main idea is to use the historical sources, such as the Icelandic Sagas and the Eddas, and to blend those with the rich tradition of fairy-tales of Iceland. The setting will be based on Iceland between the years of 930 and 1220, from the establishing of the Alþing and the Icelandic Commonwealth to the beginning of the Age of the Sturlungs which leads to the civil war. The Nordic settlements in Greenland and Vinland will also be part of the setting and will be detailed in the book.
The main aspects of the mythical side of the setting are the Elves (The Hidden Folk) and their Hidden Kingdom. In Icelandic legends the elves look very similar to humans, but are invisible to humans unless they want themselves to be seen, and they live in a kingdom somewhere in the Highlands. There are also trolls, giants, sea-monsters, magical beasts (Icelandic tales have many intelligent animals), land spirits, and more. Different mythical creatures exist in Greenland and Vinland, and those will be discussed in the book as well. And there is runic magic, which uses a new system which expands on the magic system from the BRP core rulebook.
Mythic Iceland will be primarily a fantasy setting but will also contain advice in every chapter about how to adapt the information presented in the book to use in a purely historical game.
There is no release date for Mythic Iceland yet, as it's still being written, and the name of the book may change as well.