NT 4.0 to Win 2k Server

I am about to upgrade a Win NT 4.0 Domain controller to
Windows 2000. Every other member server is a Windows 2000
machine already. This is a production Domain that hosts a
website for external clients as well as internal
employees. The current format for the name of the site is
domainname.com. If I upgrade the domain controller to
Win2k and name the domain domainname.com (same as the
website), will this cause me DNS problems for internal
and/or external clients attempting to reach the website
which has its own IP and is hosted on 2 member servers in
a NLB Cluster?

Any help greatly appreciated!

Patrick G.