Stop and think for a minute...
Who's going to teach this then? Anyone who's vaguely competent at programming probably isn't going to be working as a teacher... So students will be taught by dullards who have no real-world experience of programming and this will therefore soon degrade into copying examples from a book with no explanation of how/why they work. The reason why the GCSE curriculum is so application focused at the moment is because this is all your standard IT teacher (lower 2nd degree in Comp Sci if you're very very lucky) is capable of.
School group sizes are roughly 25 pupils of mixed ability, the majority of this group will struggle to write fluently in English let alone something as totally abstract as Visual Basic. Furthermore a significant proportion of the group will be Polish/Lithuanian/Romanian which will make this even more difficult. At least two members of each group will have substantial behavioural problems and will need constant supervision to make sure they don't try to self-harm/masturbate/fight/start fires during the lesson.
Schools get Microsoft software for a massively reduced rate so will all choose to use either Visual Studio or something like Small Basic. Not necessarily a bad thing but there will certainly be no Java.
Technical support in schools is very poor (pay peanuts principle in effect) so when the software/hardware fails it will not be fixed until the end of the school year and students will have to share computers.
To me this sounds like a very good idea that just hasn't been thought through... I'd love nothing more than for students to be taught programming and computer hardware as part of the GCSE curriculum but the simple facts are that many of them still don't have an adequate grasp of basic maths or English by this stage..
It's also quite clear that those proposing this grand idea and the majority of people commenting here (teach them to program in assembly language etc.) really have absolutely no idea of just how bad the UK education system is....