These are the dates that I've found on our internal fileserver somewhere:
End Of Sales 31/10/2010
End Of Life 31/10/2015
There was also a note from a colleague that the MD date most of the time is the EOS + 1 month, so in this case it would be:
Manufacturing Discontinued 31/11/2010
I don't know it these are correct, just FYI. A couple of months ago we were able to successfully RMA a ES 470 48t because of a faulty fan. I really hope that they are still being supported as we're using quite some ES 470's at our remote sites.