Active Directory WINS and DNS

Hello

We've recently converted an NT4 domain to 2003 AD. When I say
converted, we really created a completely new forest, and just started
migrating user machines into the new forest.

BUT

When we did the migration of desktops into the new AD forest, we used
the Netbios name of the forest "CORP". When in actuality, the DNS name
of the forest is "CORP.COMPANY.LOCAL".

My question is...Now I'm ready to kill my NT4 Wins servers. Will my
clients that are looking at the NETBIOS name, be completely lost until
I change each one of them (450) to point to the FQDN?
Any help is appreciated. TIA!