WINS decreases client NetBIOS broadcasts and probably improves network performance in a /16-network when not having all clients broadcasting to every other client. NetBIOS is a broadcasting protocol which isn't routed, and neads WINS/NetBT (NetBIOS over TCP/IP) to be routable. You should keep WINS if you nead to use NetBIOS for network browsing or other application depending on it, otherwise it can propably be skipped if you can disable NetBIOS broadcasting.
Article about disabling NetBIOS
http://www.petri.co.il/disable_netbios_in_w2k_xp_2003.htm