What you are thinking of doing is incredible similar to an existing attack known as the karma attack, made popular by the super fun Wifi Pineapple.
The basic principle behind the attack is for the attacker to setup an AP that responds to the wireless probe packets clients send out when attempting to connect to a previously trusted AP. By responding to each individual packet on an individual basis, the attacker can force the client to connect to his rougetheir rogue AP.
When combined with a deauthentication attack, this is an incredibly effective tool for performing MITM attacks.