So how would you and your school implement a Computer Science course below A-level?
If your answer is that you would never implement such a course, then the RaspPi is obviously surplus to requirements. However if you do intend to implement such a course I would be interested to hear what hardware you were intending to use.
For a start, unless you are a 'free school', an academy, or a private school, you'll teach whatever the national curiculum tells you to, which at the moment is ICT.
As things stands, I expect that Rpis will be used in LEA schools (either in primary or secondary sector) in after-school clubs, and wont be part of the main-stream curiculum for a good few years.
There's nothing wrong in that, of course, but the idea that millions of school kids will get their hands on one is just 'pi' in the sky at the moment.
PS. As to the VGA question, I checked and at my son's secondary school, all monitors that the pupils use are cheap Dell panels, with VGA connectors. Like most schools, they have not bought new kit in bulk in the past few years when DVI became more popular, and in the current economic environment wont be doing so for a while.