With the final, official version of Eberron out now, I notice that dragonmarked casters now get their mark's spells (up to 5th level) as bonus spells up to. This has two effects. 1: You can bypass spell list and (for Eldritch Knight/Arcane Trickster) school restrictions. Any Mark of Passage Human in a gish class is a Blade of Orien 2: It seems to me multi-classed casters get these spells as soon as they have slots of that level.
Battle Smith artificer gets intelligence to attack and damage in place of normal attribute. This is only with magic weapons, but like the original artificer you can create your own.
Has there ever been a detailed (locations listed) map of Arenal before? Xen'dirk's map is a lot more detailed than it has been.
Common magic items can be purchased for "2d4 x 10 gp, or half as much for a consumable item such as a potion or scroll" and be found for sale in any city with a DC10 investigation check. Among the common magic items are functional prosthetic limbs (something Eberron hasn't been particularly clear on previously), stones that clean anyone who touches it that are explicitly common in public areas (self reseting magic traps are back!).
There's a map on page 269 that sorta (it's a map shown from top and side and has scale in the top view) indicates how high Sharn's towers are, which was never clear before.
Also the elf on page 49 looks suspiciously like the PF Rogue iconic. Not even exaggerating.