There's a process. It happened in Shoreditch, Hoxton, it's now even starting to happen in Clapton and Homerton, Hackney Wick, all kinds of places that a few years ago you would have found it hard to imagine as places like that. Artists and others with not much money move to a place because it's cheap but relatively central. They do stuff - put on shows, club nights, etc - that brings others into the area, and the area becomes known as somewhere where stuff happens. And other people with a lot more money start wanting to move to the places where stuff happens. Eventually, the kind of people who made the place in the first place can no longer afford to live there, and the nature of the stuff that is happening there changes, becomes safer, more corporate.