I've been to New York and London, and nowhere did I see the sickening stuck-up attitude that I do around here.
You've only "been" to London, whereas I have lived there for a third of my life. I can guarantee that there are plenty of arrogant, stuck-up, self-obsessed and money-orientated people there. Though I would add that this is the case in every major city I've lived in, these days at least.
Capital cities tend to have this on an even higher level, though. In some ways, it's justified - capitals tend to attract the ambitious (like me :) ), and it's true to say that I've achieved my greatest successes in London and not elsewhere. The downside is that you usually have to live in a totally different way to achieve this within capital cities (higher costs, longer travelling times, less space, more crime, no car, etc), which is partly why some people who live in places like Warsaw or London may think they are "better" - they aren't really, but if you are willing to endure certain discomforts in order to achieve success/money, it's hardly surprising that you may look down on the unambitious people you left behind.
This probably makes me sound a bit stuck-up lol, but I'm not, I'm just trying to explain that places like London are virtually a separate state within a country, and the rules are a little different there ;)
I like Warsaw - it's the only Polish city I really feel at home in, but I think that 12 months there would be more than enough for me.