3 years on, for anyone worrying about not hitting their target grades for uni:
All of my offers ended up being higher than my predicted grades, and I only achieved 2 of my predicted grades anyway. Really should've picked more relevant, easier A levels like IT and business, rather than taking maths and chemistry which I was never good at during GCSEs but wanted to do because they'd "look better". Nope, A's look better to uni's who don't care what course they're in, not B's and C's in harder subjects.
Also, beware of letting your A Level teachers inflate your predicted grades to make themselves look better. How a whole class that never achieved higher than B's in A level maths mock tests, and were more regularly achieving low C's, were forced to tell universities via UCAS that they would achieve A's is beyond me. At least a few met their targets, but I wasn't the sort of person to study 5/6 hours per day after school for subjects I wasn't enjoying.
However, I got a job at a local software company as a full time junior software engineer within a couple of months of finishing my A Levels, turned down my place at Sheffield Hallam uni and took on a part time course at The Open University studying a BSc in Computing & IT and Mathematics. Now I'm probably in a better place than I would be if I'd been to uni, as I was promoted to a mid-level engineer within a year, the company was acquired, I bought a house, and I'm halfway through my degree with tonnes of experience in the industry that I wouldn't have had for years to come had I gone to Sheffield Hallam (my 3rd choice) or even been accepted by Uni of Sheffield (my 1st choice).
So I guess offers / UCAS isn't as important as I thought it was when I posted this 3 years ago, and there are other options that might be better suited to the individual, despite sixth forms and colleges pressuring all students to go straight into full time higher education and making it sound like anything else is sub-par.