That's a lot of questions. Tell you what, how about I split these up into groups and answer when I can?
Dr. Strangemonkey> What can you tell us about some of the antagonists in Arcana Unearthed ?
Well, of course AU doesn't have antagonists, it's like the PH. The follow-up book, the Diamond Throne, however, presents a lot of interesting foes, like the chorrim, which are sort of like militaristic, crafty ogres, and an archvillain called the Blue Knight, who literally seeks the death of every living thing.
CharlesDM> A question for Monte - Nostalgia has played an important role in the popularity of 3rd Edition and d20 products. Are there any elements of nostalgia designed into UA beyond the title?
I'd say not too many. If anything, it's a step away from nostalgia. I love D&D, and love all the D&D standbys that have roots in nostalgia, like magic missiles and whatnot. AU is a chance to look beyond that to get something with a slightly different feel.
Merlion> Can you give us an example of how many spell slots and readied spells a day a 1st level character of a spellcasting class(any one will do) would have in AU?
That's a pretty specific question. A magister without ability score mods gets slots of 3/1 and spells readied of 5/3.
DarkPsion> How are Psionics intrigated in AU?
It depends on what you mean. If you mean Psionics Handbook style psionics, that will be as easy or hard to integrate as it is with core D&D.
However, one thing that I've done is create certain classes, like the mind witch, and races, like the verrik, who are very "psionic."Psionic" in this sense means that they have mental based innate powers like telepathy, telekinesis, and that sort of thing. So it's flavored just like psionics, but the rules are not Psionics Handbook-ish at all.
Leiff> question: You mentioned that psionics is going to be built into the magic systeym (by taking a feat), and that being a priest type would be a feat as well (with social influence, not divine magic). Are there going to be any other interesting twists with magic types?
Lots. With the Arcana Unearthed rules, you'll be able to play a wild mage, an elemental mage, an energy mage, a war mage, and many other different twists on magic types.
RBB> Monte, the (core 3e) illusionist seems a bit watered down from the Unearthed Arcana days. Is Arcana Unearthed going to liven up illusion magic or make, say an illusion-focused magister interesting? I'll take my answer on the air.
Well, to be clear, no AU spellcaster focuses on a specific school. That said, there are plenty of new illusion spells in the book, and they could easily be adopted into an D&D illusionist.
Merlion> : Can you tell us a little more about how various classes aquire/learn/change spells in AU?
Merlion> :Can you tell us a little more about the Witch's Witchery and the Runethanes runes?
For both of these, I really recommend just checking out my design diaries found on my site. I think they answer these better than I could here.