One of the subtle problems in any network environment is security. Any new automation system has the potential to open up doors for mischief. DHCP's automatic registration process makes it easy for you to hook up a laptop and tell the network that it's you. But it also makes it simple for someone else to do the same thing.
Network administrators will need to be aware of the potential for spoofing and users who might masquerade as others. Microsoft points out that this problem existed before. This is certainly correct, but the inflexibility of the old IP routers hobbled some of the efforts of spoofers. An administrator had to type in the MAC-code from the network interface card on the machine into the IP address database before the spoof would be complete. The automatic registration process makes it easier for someone to completely assume the network identity of another.
DHCP has enough of the old ``inflexible'' IP configuration procedures built in to circumvent this problem if it occurs. It is possible, for instance, to direct the DHCP server to always give a certain IP address to a certain computer, although this defeats the purpose of the dynamic DHCP system.
Many network administrators will probably choose to ignore the problem of malicious users and choose the flexibility of a fully functional DHCP. The trade-off will certainly be worth it for many. DHCP doesn't introduce the problem of masquerading users, it just makes it slightly easier. The most secure environments solve the problem by using cryptographically secure protocols for establishing identity. It is clear that the world is reaching a point where an infrastructure is needed for authentication that would allow people to identify themselves properly on the network.
Security
