There is a great article in this month's Vanity Fair about Brits living in NYC. I hate to be so unpatriotic, but its funny cos its true:
http://www.vanityfair.com/culture/features/2007/04/brits200704
I also agree about with what was said about food. London has some incredible restaurants, (Also, I do occasionally miss Sainsburys), but NYC wins hands down for good cheap food (shout out to the Park Slope Co-op massive! Stay crunchy!), available at all times of day and night, and a far better selection of dishes.
London, however, shits on NYC from a great height when it comes to clubs. This place is such a disappointment in that respect, but that's about the only thing NYC isn't better at than London.