I gave him a 6, only by taking off my Ron Paul, libertarian bias off first. From the perspective of an uneducated viewer, I think he came off weak on the earmarks, cutting budget programs like Dept of Ed, fanciful notion of eliminating all income tax. The Reagan quotes were kind of misleading, and he handled himself OK, but repubs think he is a mesiah, and is beyond reproach, so this will hurt some with them.
I think he scored well on points of us becoming a fascist empire. I think that will resonate with most libertarian leaning democrats and repubs. For the party loyalists, I don't think Dr. Paul changed their minds much. For those not much attuned with politics, they will likely find him eccentic and interesting, or some will be turned off. I think he nailed it at the very end though at may allow some to research him further.
Russert is tough as nails, and most go away with a haircut in their poll standings. Look at Giuiani's poll numbers since he soiled his pants with his grilling. Huckster will run the same guantlet and will face just as tough a grilling. I'm actually surprised any Repub would subject themself to it since Russert shows no mercy.