I think it is important to remember that the reason wands (and scrolls) were mentioned in the L&L article: these magic items have been responsible for helping promote the image of the 'broken' wizard. They allow the magic user to easily (or at least at small cost during down time) circumvent some of the limitations placed upon their spell casting.
Personally, I favour using the idea that Mike put forward for scroll on wands: they allow the user to expend a spell slot of the appropriate level to cast a particular spell, thus giving the caster a bit more flexibility in not having to prepare a particular spell (or perhaps not even knowing it). Maybe they can enhance the level a particular prepared spell is cast at. This seems useful and flavourful without being too abusive. Scrolls could follow the long casting time or Ritual method: this would limit them to utility type spells, as combat spells would be less useful in this paradigm, but that is what wands are for

. Maybe a scroll niche can be casting spells above the level you can normally cast. Sure, it might take a while for that sorcerer to cast from that scroll, but if he gets that
Meteor Swarm off with you only being 7th level, you're really going to feel it. I can see a scenario where the magic user is trying to cast a higher-level-than-he-is-normally-able-to-cast banishment spell from a scroll while the party tries to keep the demon off of him. Scrolls could still be useful for transcribing combat spells to your spell book as well.