In an article in the Evening Standard, Ben Rogers (who directs the new Centre for London) argues that moving the poor our of London will not do much to help address poverty.
I am sure he is right but, as the article also acknowledges, allowing them to stay put doesn't do much to help address their problems either. If you want to read more on the evidence, take a look at our SERC policy paper on the effects of mixed communities. That paper also talks about some of the benefits of segregation that Ben Rogers refers to in his piece. You can read about a more trivial example here.
On the related issue of housing benefit reform, seven months ago I published my list of open questions about the impacts. While I think we are slightly further along in terms of knowing how many people might be directly affected, I think many of the other questions remain unanswered.