(interestingly, as I was preparing this I reviewed the DMG information about monster roles, and I have to say that the PHB wizard looks much more like Artillery than Controller by the DMG monster definitions! But I digress)
Actually, if you take a look at the NPC/class templates, you'll see the wizard is in fact Artillery and the cleric is Controller. Monster roles and PC roles don't mesh, I guess...
Anyway, when I saw the thread title, I thought you meant ALL controllers, but given the limited info we have on druids/invokers, I'm not sure what could be done about them.
But I see you only mentioned the wizard, so I guess this is more of a wizard specific problem at the moment (emphasis on ATM). So let's fix him.
I suppose if you remove his minion clearing abilities (big area, small damage), you could improve his power selection in a case-by-case base. You could steer him a bit towards leader by making some new area powers that affect enemies only (like shooting a number of guided missiles instead of the typical burst/blast), or towards striker and make some one-target Ranged attacks with big damage (maybe not so much as the warlock's) and some added status effect, making him more "artillery".
I think wizards need more usefull encounter utilities for combat. More of those would be nice. I guess this will make the dailies seem less atractive, and it might have some unforeseen issues with the spellbook feature, but I'd feel more usefull to my group if I could use my powers more often instead of waiting for the right time (that might never come).
Another way to go is messing with his class features, and add a couple of new Implement Masteries to choose from (like Wand of Reach, Staff of "You Shall Not Pass" or whatever), or even some new implement proficiencies (it seems rods are good for dealing damage, it could have been a problem when he had all those enemies in those big bursts, but with single targets? not so much, i guess...)
Or you could improve the wizard's shtick: options. He already has cantrips and lots of rituals, but no extra combat usefullness. So, give him more at-wills and maybe say the spellbook works for them to: A wizard could have 4-5 at-wills to choose from and prepared 2-3 of them after an extended rest. Or maybe just let him have one extra at-will slot and prepare one out of 3 extra options after each short rest. It feels good to have the right spell at the right time, even if you do the same damage, you can choose an additional effect and the right element to throw against your foe's vulnerability.
Another idea I was toying in my head these days: make him the master of arcane spells. Let him multiclass as normal but use Intelligence when calculating the attack bonus of an arcane spell instead of its original ability modifier (attack but maybe not damage, perhaps with a paragon path or feat). Multiclassing into Warlock or Sorcerer would be fun.

Hmm.... Perhaps an Archivist variant for divine prayers... But I haven't thought this through and it might be incredibly abusable, even though it already costs a lot of feats to multiclass.
I'm not sure this is what you hoped to hear and I'm sorry I don't have any solid play-tested house rule to invoke. I love the wizard class, but I also feel like it could use some extra lovin'.