Here's hoping you'll say things like:

1.  More love to life and death magic

I really liked how Master of Magic incorporated Life and Death magic along side their elemental magics.  This would give players the option to play a little good vs. evil even though we know there are no good vs. evil factions in EWOM. 

2.  10 spell levels instead of 5

Having 10 spell levels will allow us to do spell mastery.  For example, you can reach 5 spell levels in several realms of magic or you can master one realm magic (all 10 levels) if you choose to abandon (0 levels) its opposite.  If you remember, Master of Magic had a version of this mechanic.

3.  Speed up spell learning

It's good for techs to take a long time to learn, but spells should come a little faster in EFE than they did in EWOM.  With the focus supposedly on "magic", we need access to a lot more cool spells here.  By the way, I think the books of combat and summoning should be incorporated into life, death, fire, water, earth, and air.  I think the books of mobility and enchantment should be basic magic spells that all casters begin with.  You can sprinkle more powerful mobility and enchantment spells in the other books.

4.  Wearing armor hurts the spellcaster's ability to cast magic

Have you considered making spell failure rates based on the amount of armor the spellcaster is wearing?  25% failure for leather, 50% for chain, 75% for plate?  It would be nice to have our best spellcasters actually look like a spellcaster and be vulnerable to melee attacks.

5.  Harness the power of all schools of magic... In EWOM, fire magic is clearly the best.

Air Magic: I would like to see more damage and randomness with lightning strikes (lots of damage, but chance of damaging your own troops).  The wind spells should have the ability to blow people all over the place during a tactical battle making it very difficult to ever get near you.

Earth Magic: I would like to see the ability to interact with the objects on a tactical battle field.  If an enemy troop gets 1 tile away from a tree, an earth sorceress can command the tree to grab the enemy for x turns, pick up a rock on the battlefield and drop it on a foe for damage, cause a giant statue to fall damaging all troops in its path, open a crevice that blocks movement to that tile, slow an enemy in mud, etc.  Hopefully, you are planning on interactive objects on the battlefield map.

Water Magic: I would like to see more freezing effects with all water spells.  How about a Call Winter spell which turns the battlefield into a snow map which causes fire spells to do 50% less damage.

Life Magic:  With the ability to resurrect (stays permanently even after battle), Cast Light spell which renders death magic 50% effective, etc.

Death Magic:  With the ability to raise dead (temporarily on the battlefield, dies again after battle), drain life spells, etc.

6.  The spellbook and magic casting UI needs love... Jon Shafer, where are you?

The ability to sort the spellbook alphabetically or by spell level or by realm of magic or by casting cost, etc.  The ability to see all spells in a particular realm even if we haven't learned them yet... kind of like the work you're doing on the tech tree.  It would be nice to have some unique and random spells every game... kind of like the work you're doing on the tech tree.  And finally, a spell toolbar like World of Warcraft.

7.  The ability to use summoning spells during a tactical battle.