I noticed this over on SO, and didn't even know this was the case there:
The answer (quoting from Jeff Atwood) was:
It is our strong belief that if you accept an answer in less than 15 (now 10) minutes after asking the question, you have not given the community an adequate chance to fully answer your question before rushing to accept.
I'm curious if this has ever been discussed as being implemented on ServerFault? NOTE: I'm not in favor one way or the other. While most questions tend to take 10 minutes or more to accept there are some where the OP gets a quick answer and then just accepts it, whether right or "best" and then the question either dies or another expert's "better" answer gets neglected.
However, on the flip side, it also means that the OP has to bother to come back after 10 minutes if the first quick answer is truly the RIGHT one.
Personally, I don't think the issue is with the "answers" but with the "questions"...however I'm still curious why such a prominent feature there on SO was never implemented here on SF.