I do like the new feature where bringing up your spellbook automatically selects the last spell you cast, however it does have one problem:
You can't scroll up.

Not right away, anyway.  If I try to use the mouse wheel to scroll up the spell list, nothing happens.  Instead, I have to scroll down first, then I can scroll up.  While this is a minor bug and there is an easy workaround, I find it to be far more annoying than I probably should.  It's really annoying when I've been casting Raise Earth (bottom of the list; very underrated spell), and then I try to cast a city enchant (top of the list).

If it's somehow an easy fix, please fix it.  If it's not an easy fix... There are more important bugs to fix.