I just thought I'd say first off, as a new member, that you all are awesome.
Now... I have an E6400 as well.
I've been able to get pretty far with mountain lion, but things that aren't working right now are:
Sleep (I used DaFOB's method, it didn't work, it didn't even shut down right the first time, and now the only thing that works is shutdown, I tried sleep enabler, I feel like I did something wrong because it KP'ed so I'm reinstalling)
Audio (I used VooDooHDA 2.7.4 and it was better, however the controls became useless.)
And finally WiFi I got working, however it wasn't able to be fixed by that intel driver, I had to look elsewhere for the broadcom one.
Before I had a go at SleepEnabler (not the one listed as working on this page) I had everything except audio, and obviously sleep working.
If there is anyone who can help on here, please let help