Reason being that people with all those euros will sell them and flee into the dollar.
Financiers, yes, but average people are somewhat trapped.
Money is flowing generally from southern Europe, where the banking system is going down, to northern. Gold is doing well despite taking an initial hit right around the time of the MF Global fiasco.
Bear in mind that the crises are being "managed" at a high level. Greece and Italy are in the news...but the UK is not?!!! California and Illinois?!
The dollar is not in trouble--yet--because it was decided at a high level that the crises would be managed piecemeal,with the most "expendable"--least influential--economies dealt with first.