My understanding is that you can:-
create a fake AP (have successfully gotten working)
disassociate clients from a genuine AP and if their computer is set to reconnect automatically it "may" connect to the fake AP if the signal is strong enough. Alterntaivley if your windows box is set to connect to an AP automatically but currently isnt, the fake AP can be set to use the SSID being brioadcast by the windows machine to create a fake AP. (have got this part working)
to obtain the WPA key you would need to run Metasploit, which will only be successful if the connected machine is unpatched and has certain firewall ports open. Once the box is broken you could install wirelesskeyviewer or alternativley run the wirelesskeyharvester (see other thread - although I havent managed to get this working), another alternative is the rogue updates such a notepad plus etc (again not managed to get working)



