User blog comment:Odisseas25/Why does the AP go to mid?/@comment-4834593-20130210132349/@comment-6301771-20130211231110

That would depend greatly on the support, and would leave a lot of vulnerability for the AD carry (or even someone else, depending on how crazy we're getting with lane-rearanging.)

Another major problem I could see is junglers: Suddenly, mid is very, very full, and that can make crossing too close to the center of the lane risky, and means both their roaming and ganking potential is down immensely. The addition of more areas to ward also gives a massive amount of map awareness to both teams, making the jungler's job even harder.

Still, if managed correctly, having people in the "wrong" lanes and blatantly ignoring the metagame can help pile drive through unknown weakpoints. For example, Pantheon mid is a zoning machine, and he completely shuts down most mid's early games. Talon mid is also a frightening proposition, given his silence, and almost any assassin, carry, or even tank could disrupt mid to the point of either drastically reducing their end-game potential, or plowing through for an early win.