Stack Overflow is the ultimate long-tail resource. My favorite example of this is, what I consider to be, a very obscure question I asked then answered about getting (http://stackoverflow.com/questions/570076/netbeans-forwarded...) anti-aliased fonts and sub-pixel rendering working when running java software on a remote X11 server. This sort of thing is incredibly esoteric, yet, close to 1,000 people have looked at it in the last year. When I asked the question, and found the answer, there was no useful information that I could find about it, yet when you search on google today for 'x11 java anti-alias' the first result is my question, and the second is someone elses.
No, unfortunately it wouldn't. The google juice is completely concentrated on the stackoverflow domain — I constantly find insta-moved SO questions at the top of the search results, with the moved question on SF or SU nowhere to be found. Yet another defect of their asinine community silo policy.
They don't do a 301 redirect — how would google know where the real question is?
we do a 301 redirect if the stub is deleted. We probably should be auto-deleting the migration stubs after a period of time but haven't gotten to that quite yet.
We've come a long way since expertsexchange.