It's getting a lot more popular! I don't think it has quite the status it has in America, but it has grown massively in the last few years. When I was first home-schooled, it was still quite a weird thing to do, but by the time my younger sister was of secondary school age she had several friends locally who were also home-schooled. At the dancing school she was at, there were about 5 home-school families.
The interesting thing is that the stereotypes of English and American home-school families are totally different. The popular imagination seems to see American ones as being ultra-conservative, Bible belt type families; while the English ones as seen as being hippies and probably pagan. I don't know how that came about!