I've always disliked the memorization system. All it does is limit your spell versatility, and make mages worthless at low levels and broken at high levels.
If you don't know what you're going up against, you're not going to bother memorizing interesting situational spells. Instead you just memorize all your combat spells. "I can memorize Featherfall or Fireball? Hmm, let me think about that one..."
Likewise, early on when you're severly limited in the spells you can cast, wizards are worthless. "I can only cast Magic Missles 3 times today, and am fragile like a dandilion, so unless things start looking dire, I'm going to be standing in the back, throwing paper airplanes and glaring at the enemy." To make up for which, wizards are completely broken at high levels, able to destroy whole groups from range.
Besides, there have been plenty of D&D computer RPGs. We're not constrained by D&D licenses here, so let's get away from D&D. Let's do something different for a change.