I have learned that this Windows network service is not required any more in a Windows 2000 or up network environment. However, I still use it on any Windows 2000 or Windows 2003 network environment I am working with because I have also learned from my previous experience that it works much smoother than without it, especially for the reason that we are still using NetBIOS name (computer name) a lot more than a FSQN name (domain name). Besides, it doesn't hurt or add a lot of overhead on your existing network.
Today, by reading one of the Q & A from the recent issue of Exchange & Outlook Administrator, I have also learned that there is another reason why we still need to keep it. The original question is whether Exhcange will suffer if WINS is removed, and the short answer is:
So...WINS is still alive, for certain circumstance, we do need it in a Windows environment.