Further information: The card now lists (lspci) as Atheros AR8151 v2.0. I get the same problem with the most recent business-card size net install, downloaded and install attempted around 9PM New York time, Jun 11. (1 PM New Zealand time, Jun 12).
A net-install that can't find the NIC is a little less than useful. :-) Anyone have a clue as to what's going on? Did I maybe catch the weekly build in a partially-complete state? Phil