I want my own enterprise dynamic DNS server!

Biff98 writes: We manage thousands of hostnames for field gear with DynDNS.org. It's always been our intention of configuring our own DDNS server and bring it in-house. Given the recent DynDNS outage due to a DDOS attack, resulting in the inability to resolve names for multiple days, there has been "encouragement" from management to move forward on bringing DDNS in-house. The problem is I can't find any easy-to-use, scalable software to accomplish this task! BIND doesn't scale well, and I don't consider MintDNS an option due to the required platform (Windows Server w/ AD & IIS). Has anyone out there solved this problem before?