I'm not in London, for me the geeks/normal split oseems fairly even between iPhone and Android e.g. a female, non-tech colleague who went into the store wanting something with a hardware keyboard and came out raving about Swype while my tech colleagues all have iPhones.
According to those results, 31% of android users are earning £10-20,000 vs 13% for iPhone. In the £20-30,000 category the positions are reversed. On the other hand, Symbian users seem to be even more affluent so I'm not sure this proves anything.