You MAY be right. Of course, they have been rather critical of McCain since the Palin pick.
I think International Capitalism is at a crossroads. Neo-liberalism has dominated the landscape since the Reagan-Thatcher era (continued by the Clinton administration and the Dems and, of course, "W") and it has arrived at a crisis, where it will need to be reconsidered.
Despite all of the silly, political slurs that Obama is a socialist, he is/will be a servant of capitalism. My guess is that the Economist (and the Davos folks) want someone they feel could better adapt to the situation at hand. McCain might have his hands tied by the ideologues of his own party.
I also feel like a lot of people, even serious Republicans, have trepidations about Palin being a heartbeat from the Presidency.