Interesting question - I'd quite like to know what happens here too.
Matt Cutts recently posted a video on cloaking (http://youtu.be/QHtnfOgp65Q) saying that as long as you don't do anything 'special' for Googlebot you're OK, but presumably if you are redirecting IP's based on location and you don't want to prevent Googlebot form accessing your site then effectively you have to do something 'special' for Googlebot (e.g. you're doing one thing for everyone else and a different thing for Googlebot).
