Is it necessary to include and update the status of a paper on arXiv once it has been accepted for publication in a journal?
My practice is to replace the initial preprint with the postprint as soon as it is accepted.  After it is published (electronically), I go back and add the DOI and such.  The reason for this is that the paper is often significantly improved during the refereeing process, and I'd rather have people reading the improved (postprint) than the original preprint.