Here's the most important question IMHO:
Will there be any way for someone who already owns AU and the Diamond Throne and doesn't want to spend a ton of money on mostly reprinted material to seprately get only the new, updated info found in AE? Will future supplements to AE also be fully, 100% compatable with AU, or will there be new classes, feats, powers, spells, races, etc found only in AE that will throw owners of AU for a loop? What, if anything, is being done about this?QUOTE]
Here is what Monte says on his FAQs:
If I already have Arcana Unearthed, do I have to buy Arcana Evolved?
No. Arcana Unearthed is still a great game, and as I previously mentioned, the two books are fully compatible. But it all goes back to what I was saying about “more.” If you’re an Arcana Unearthed player and you crave more—more of everything that is Arcana Unearthed, really—and you want to have all this material in a full-color, complete volume, you’re going to want to get Arcana Evolved.
How much is this book? Contrary to what you may have read elsewhere, the price for this giant full-color book is $49.99. That is for the 416-page hardcover version, due out in February 2005. At the same time, we will make available a full PDF verrsion of the book, which costs $23. If you just want the the important errata and clarifications introduced in this book, we'll have that online here for free.
The new Race, the Drachna are on preview here:
Drachna Race
Even the "new" Champion causes (Knowledge and Justice) have been free Web Enhancements once (though I can not find them any more on the boards).