Suggesting that users open their working device in order to "prevent" this issue is so ridiculous, that it does not deserve a comment.
The only way to fix this issue is by Nokia issuing a statement (and standing by it):
"Every N900 with detached USB connector will be fixed/replaced free of charge, regardless of user handling or warranty issue".
Saying that it will be solved according to warranty is not good enough, since even if the connector manages to hold for a year and then breaks, it is still a bad design by Nokia, and should be replaced. Saying that it will be solved according to warranty and then refusing to fix (as is the current state) is so much worse. The only way "we" can help to fix it is by giving this issue as much publicity as possible.