Now I know that many people will form an opinion on this suggestion simply because of its title.
This suggestion is different than any I have seen on the site so far, so it is new and hasn't already been declined.
Currently the option to give Neutral Rep is disabled because @Philly said it is useless, but I had an idea!
I think that Non-Upgraded members should be able to give Neutral Rep. That being said, I think this for a few reasons.
Seeing as they haven't upgraded and therefore haven't earned the right to affect others reputation points they can still form opinions on others whether that be good or bad.
This is where neutral rep comes into play, because it gives non-upgraded users the ability to leave their opinions on others in a nice and neat place while still not affecting the user very much.
When other users check another users rep they may see some neutral reputation points, showing what non-upgraded users think of this other user.
Basically, it allows the non-upgraded users to speak their mind without giving them too much power.
Along with this new found power should come some consequences though. If a user is abusing their rep powers and just leaving bad/rude comments on other peoples profiles for no reason then they should have their ability to give rep removed.
I think this could be useful, and potentially make the community closer.
OR
It could go horribly wrong and tons of multi's and newbies could go around being dicks to everyone because "they can".