DoomScythe,
I will try to give my opinion on BullHorn's message:
Newbie: Person who can barely figure how to start his PC, let alone install anything and/or use a program or play a game (I can see these often here in Israel ._.).
I think this is close to my 'definition' above, just push the button and play games, write homework in office, or write an email to friend using webmail. These people do not install new software themselves. Autologon enabled?
Acquainted: Person who can do simple actions with a computer like install programs and games and just have fun using a PC without actually knowing what he is doing.
The first one who is able to download and install new software? Is very vulnerable to infected downloads. Is not able to fix problems with PC but is able to find help if something goes wrong.
Is able to chat in webchat. Still zero security knowledge except user/pass login.
Intermediate: The most common level of PC users, in my opinion. They know how to fix random simple problems, formating, installing Windows, know how to use Google, etc.
I agree except thath this is the most common. I think this is the most common level of users that you can 'meet' on the Internet but I am not sure that this is the most common level in general. I think people in offices using only one software to do their job are not on this level and they are the majority I think.
Skilled: That's how I see myself. I know what I'm doing, I can fix almost any problem myself and even if I can't, I can easily find a solution. I can keep my machine free of problems, and fix the machine of problems incase I acquire any.
I think this is quite a big skip compared to the previous group. But ok. Maybe this is the first class of users that maybe try something with 'alternative' software (I am talking about Mozilla, Linux, OpenOffice, ...). Lot of application level programmers can be here.
Expert: People who actually get paid from doing computer-related works, know how to code in at least one language; the people that "Skilled" users go to when they have a serious problem, like people that are part of the Comodo crew.

I would put low level and security programmers here as well as skilled system and network administrators. Not always paid - I am talking about college professors and students who often create free, open and academic tools and projects.