Lord Turner came out with his proposals (in the loosest possible terms) to manage markets through specified taxes on certain financial products, services and practices that are deemed problematic.
Cool, let's have some of that.
What we're talking about is disincentivising certain actions that are deemed not 'socially useful'. That's very subjective, but at least there does seem to be some change in what is seen as socially useful. In the recent past, making lots of money was seen as a socially useful end in itself. The crash has, to some extent, moved that understanding so that people are not so in awe of big money