Skeletons are getting Tonberry-like skills, like I envisioned in the last Newtype. To that end, they're more physical than magical, being more like Skeleton Knights. There will be a lot of spells given to monsters, though. Hemogoblin (thanks to PX for the name) would get Drain/Osmose, Avians would get the Aero family, Mindflayers would get Psionic and Water magic, etc. In fact, since the Psions learn all their skills Blue Mage style from other Psions, having a Mindflayer around might be useful.
If Kage can get around to making a Vampire and/or Succubus sprite, those would probably replace Avians and Trees. Uribos are currently out.
If Kage can get around to making a Vampire and/or Succubus sprite, those would probably replace Avians and Trees. Uribos are currently out.