Does anyone out there have, or is willing to admit working on, a
   "real" DHCP client for NetBSD?  I have two candidate uses (both the
   obvious wandering laptop, and as a client of CATV-based networks --
   continental cablevision's IP-over-CATV system apparently requires the
   use of DHCP by its customers).

the dhcp server provided with netbsd also includes a ``(really lame
DHCP client)'' in src/usr.sbin/dhcpd/dhclient.  i can't find any
documentation on how to use it, and when i queried ted on whether
it should be installed as part of netbsd, he said "no".

however, it may be useful for what you want.  :-)