I've been looking at this too, just out of interest, as I agree with Jeff that the notion of a flat RAW file is not too important.
This is from another forum, a post by Eric Chan:
"The basic premise of PV 2012 hasn't changed relative to 2010. We try to provide good starting points with the defaults. (The default setting in 2012 just happens to have "0" for all the Basic sliders.) That said, it's unlikely that our default is going to please everybody. Photographers have personal preferences, after all.
This is the reason why we make it possible to establish custom defaults. For example, if the default image contrast is too high (even at the Contrast setting of 0), try reducing the Contrast slider (e.g., to -10). If you like that better, and you find that works better for you on several of your images, consider saving a custom camera default with that new Contrast setting.
You may find that, while you're learning the 2012 controls, that you need to spend a bit more time to find your preferred sweet spot. That's understandable. But the ability to establish your own personal starting point remains, and I encourage you to use it."
I tested it, same file, in LR3 and LR 4. Rendered tifs with all settings set to zero, or defaults in the case of LR3, are exactly the same.