I'm glad. Not only are they bloody annoying but they are dangerous - there's loads of idiots riding round on them where I work in Elephant and Castle, aka around a massive, busy subway roundabout thing and they can't balance properly! If you're out riding them near roads and stuff without any kind of regulation checking that you are actually capable of balancing the thing it's potentially very dangerous.
I have to admit I don't care that much about the danger - it's not me it would be affecting - I just hate them because they are so hideous, they take up loads of space, and the people on them expect you to move out of their way when they're taking up the whole pavement. But yeah...danger