I dislike the fact that Clerics get to wear armor and Wizards/Sorcerers don't. And I would certainly not boost their already insane spellcasting ability as compensation for taking it away.
But just to show the stupidity in Arcane Spell Failure, let me bring a few things to your attention.
Arcane Spell Failure supposedly exists because "The armor restricts the complicated gestures that they must make while castign any spell that has a somatic component." PHB v3.5 p. 56
Hmm, ok. "Complicated" as pointing at someone? "Complicated" as using sign language? I mean, seriously, people. How "complicated" can it be? What are these Wizards doing to cast spells? Cartwheels? Contorting their body in horrific ways that make the Kama Sutra look easy (shudder)? On the contrary, most of the time it has to do with gestures about as complex as sign language and giving someone the finger.
"A somatic component is a measured and precise movement of the hand." PHB v3.5, p. 174
Okay. So how does armor interfere with this? Really, I find it hard to imagine how wearing chainmail prevents you from properly performing such a gesture. If it inhibited your ability to use your arms and hands that much, how do people perform complex sword maneuvers and whirlwind attacks in armor?
And what's more interesting is that this only applies to arcane spellcasters. Forgive me, but don't divine spells with somatic components not also use such "precise movements of the hand?" That quote from above desacribes the somatic components of ALL spells, not just arcane spells.
And there is also only one spellcraft skill. A spell is identified by its components. This means that a spell has the same components no matter who uses it. A cleric performing a spell uses the exact same components (save possibly a divine focus) as a Wizard casting the same spell.
So, if a Cleric spell has just as "complicated" of gestures as an arcane spell, then why do users of arcane magic suffer from arcane spell failure from armor and not divine casters?
The answer is simple. It in actuality has absolutely nothing to do with the "restricted moevemnts" of the armor (or whatever other excuse they have come up with in the past). The designers of D&D have a strict mental image of a Wizard as a robed, staff carrying, pointy hat wearing, book worm (remind you of anyone?). This absurd rule is merely there to enforce that stereotype.
It's funny, I never thought of preists going around weilding a mace and wearing plate mail either. A holy knight (A Paladin) who fights for his church? Sure. But not an actual priest! I always see them wearing robes and maybe some incense. Being a student of history, I can tell you that from Christianity to Buddhism to ancient Egyptians, this has almost always been the case.
And what is so wrong with a Wizard wearing armor anyway? I've seen plenty of fantasy games, novels, etc where there are armored Wizards and it's just fine. And don't give me the "It would be unbalanced if Wizards could wear armor" speech. The Cleric gets more spells per day than the Wizard (plus domain spells, plus domain poowers, plus turning undead), yet he can wear any armor he wants. He has two good saving throws, D8 HPs per level, the second best attack bonus, and is every bit as powerful a spellcaster as a Wizard. If there is a balance problem, it is with the Cleric, not the Wizard. And even in the Lord of the Rings (upon which D&D was copied, err I mean inspired), the mighty Wizard Gandalf weilded a Sword with the best of them.
So Wizards don't train much with weapons or armor? Fine. Don't give them those proficiencies then. That makes sense to me. But if a Wizard is willing to get such training (by taking the proper feats or multiclassing), why not let him wear armor and cast spells? His Hps and attack bonus are still abysmal. It's not like you'll see any Wizards making successful tanks. If anything, he went to all that trouble just so he won't have to cast Mage Armor on himself all day.
Well, at lest we can take comfort in the fact that progress is being made. In 2nd edition Wizards couldn't cast spells in armor at all. At least now they can wear it (they just get heavily penalized for doing so). But, if it were my game (which it is not) I would either make it fair and have spell failure apply to ALL spellcasters, or I would simply get rid of a tired, obsolite, and asinine rule.
And that's my two cents.