I have ML 10.8.2 running on my vostro 1500. 
I have the nvidia 8400 
It requires a few dsdt changes, AppleACPIPlatform.kext (v1.3.5), AppleBCM440, a few others as well. 
The only thing not working for me is audio.. all i get is stuttering on output.. sometimes it'll play a single sound fine, but multiply sounds in a row just stutter..