There is now a petition at Number 10 to get Microsoft to lower its prices for Vista in the UK: http://petitions.pm.gov.uk/VistaOvercharge/
Whilst I don't like big differences in price between the USA and the UK I wonder if the Government would be likely to do anything about what a company decides to charge for its products. Nobody is forced to upgrade to Vista, there are several alternative operating systems around.
I personally think there are more important issues to petition against. Petitions never seem to do any good anyway.
Indeed. I bet Number 10 is wishing it never started its petition site now!