If you are running a mixed-mode network of say WIN2K and
WIN98, then yes, you must run WINS. If you are running
WIN2K/XP, then yes, you can run without WINS. However,
there is several speedbumps (literally).
You can run your WIN2K/2K3 in 'native' mode, meaning it is
running only on your DNS server. However, the WIN2K
machines will then begin to do broadcasts (sends packents
out to say "you out there?" when a workstation needs
something) whenever it cannont locate a service, need a
new one, etc. If you have a large enough network, this can
start to have a drag on your performance level, since misc
packets, in addition to your normal traffic, is being run
through your network. Having WINS enabled reduces this
drag. Perhaps when Longhorn is released this probably will
be remedied with all WIN using DNS services. Until then,
keep the WINS on.