The head of the Met Police has said he supports a 50:50 recruitment process to increase the number of ethnic minorities in the force.
http://www.bbc.co.uk/news/uk-england-london-26765540
I initially liked Hogan-Howe not least because the crime figures in London appear to be going down although some people question this.
I'd be more in favour of an initial application form to join the MET which didn't identify your Gender, Race or Religion which would then guarantee that the best are getting through to the next stage of the process regardless.
As regards the Met police having to "look like London" I haven't noticed a sudden increase in the appointment of Constables from the Roma community.