A will I ordered by post from York on 21 September finally arrived today - just over six weeks later. It came from the Leeds District Registry with a note of apology for the delay "due to an increase in the volume of search requests" and notes that they are taking steps to rectify matters.
As a matter of interest it took them nearly two weeks to cash my cheque (which cleared my bank on 4 October) so they are clearly snowed under with postal requests since Ancestry put the index online.