I read an article, from I believe the Good Times(?), talking about how many students in the UK choose to work versus going to higher education after their equivalent of high school is over. In the US at least, the attitude that is drilled into students is either go to college or ELSE. It's the attitude that I was raised with though I really wish to continue my education, I believe university isn't for everyone. Someone also told me once that in the UK, you can choose to work right after school and it's not as frowned upon as in the states.
This is just what I heard after all, that there are generally more socially acceptable options after school is over in the UK versus in the US where, in my experience, they pretend like there is no other option other than university. You would know better than me though, Vicky.
From my experience of the US university system, it would seem that US education is about 1-2 years behind the UK at around high school/first year of college level. I studied abroad in the US after 2 years of UK university and found myself in 400-level senior classes and 500-level graduate classes because the 300-level junior classes were too easy for me (I had covered them in 'freshman' year in the UK). Because of this difference in the system, the last 2 years of UK high school are approximately equivalent to the first year or two of US college, which means that by the time UK students reach 18, they have effectively covered the equivalent of some US college-level work.
In the UK, education is only compulsory until the age of 16 (the exams taken at age 16 are considered to be approximately equivalent to a US high school diploma). At 16, pupils can either choose to stay at school or to go to a Sixth Form college to study for A-levels (2-years courses to prepare for and get into university) or they can go to a vocational college and study anything from Science to hairdressing to childcare, or they can go into full-time employment or work-based training. In my UK high school, approximately 50% left at age 16 to either go to vocational college, study A-levels somewhere else or to go into full-time employment. Of those who stayed on to do A-levels, about 2/3 went on to university (some took a year out to travel first and others went straight to uni), while the rest either went into full-time employment or to a vocational college to do courses in something different.
In the US, I think there is more of an attitude that without a degree, you won't get very far in the real world, but in the UK, it's not such a big deal. I have friends who didn't go to university, who now earn more than those who did go. Having said that, a lot of people do go to university - there are currently about £2.5 million students studying at universities in the UK. As you said, university isn't for everyone - my mum has a university degree, but my dad got a teaching certificate at a college rather than doing a full degree. The older of my younger brothers and I both went to university - he did an undergraduate degree and I got undergraduate and postgraduate masters degrees, while my youngest brother (age 18) is applying to universities right now, but it's not definite whether he will decide to go yet or not (depends on his grades, if he gets offered a place etc.).