Sadly, there's no sure-fire way of resolving this situation.
You won't be able to rely on minions to take out their towers and nexus, especially if their uber status gets to the point where they can start defending their respawning inhibitors. If you get really lucky and get their nexus towers down, you could just farm minions hard enough for yours to take the nexus down a bit then try to dive the nexus. I'd consider this a Hail Mary more than anything else, though.
If you know you're going up against a team that is going to steamroll you once they get maxxed out (2+ carries), the main goal is to take advantage of the fact that they will be weaker in the early game. If you zone the carries and/or kill them enough to keep them from getting geared and leveled, your team will get powerful enough to take their nexus before they can do anything about it.
Assuming you find yourself in that unfortunate position anyway and forcing their team to split up isn't working, you absolutely have to focus the primary damage dealers down first. If they stick together and you're not killing their carries first, you'll take way more damage than you will deal out over the course of the fight and you're sure to lose.
Generally speaking? No, probably not.
Mostly because AP characters value levels over items in most cases, and in bot lane you'd be having a support sucking up XP. Overall, this would mean that the enemy's AP carry in mid is becoming stronger than the AP character in bottom lane, while the allied AD carry in mid isn't becoming notably stronger than the enemy AD carry at bot. AD carries scale with items, and not really with levels. Thus, the AD carry wouldn't really gain anything from being in mid lane.
The majority of AD carries also couldn't lane against the majority of AP carries. While AD carries would start off strong, with decent pokes, once the AP carry gets to level 6 and has a Doran's Ring or two it is pretty much game over unless they've fed. There is no way an AD carry can keep up with the raw control and damage of an AP mid. Regardless of who the mid is.
The only exceptions to the above rule would be Corki, Ezreal, and possibly Urgot. Corki actually does scale with levels, as does Ezreal to an extent. Urgot is just innately tanky with super long ranged harass. ALL of those characters would have mana issues though, and would have to rush a mana regen item to compensate for that. And Corki and Ezreal would still have trouble with high burst/high CC champions such as Cassio/Annie/Ahri/Karthus/Just About Every Popular AP Mid Right Now.
Specifically speaking? Sure!
There will always be specific situations where you could counter certain champion picks by using more elaborate strategies. This is where a lot of the original "meta breaking" strategies come from. Such as running kill lanes in bot, double AP carries, double AD carries, or even double jungle. It can work in certain situations, but it won't work on a regular basis. And will rarely if ever work in solo or duo ques.
Best Answer
This is a developer in-joke, similar to how the 3 ninja champions obey the Inverse Ninja Law, or that Leona's passive deals 1 less damage to champions with sunglasses.
In this case, you first have to know that Zilean is named after developer Tom "Zileas" Cadwell, and Volibear is named after Travis "Volibear" George. These buffs are tongue-in-cheek references to a long-standing forum faux-feud (or maybe real feud? Who knows?) about the plausibility and desirability to add an armored bear champion to League of Legends.
Zileas was against it, and Volibear was (clearly) for it.
It's pretty crazy.
The Forums got pretty riled up too.