I couldn't agree more! It's nice to see corroboration in recent commentary by Jeff Doyle on the overall disciplined approach for IPAM encompassing IP planning, DHCP and DNS. In his article for Network World, Jeff states that an IPAM solution is even more necessary with the advent (or onslaught?) of IPv6 deployment. Dotted decimal IPv4 address allocations and assignments can more easily be tracked in spreadsheets or homegrown solutions than can IPv6 hexadecimal.
In addition, Jeff highlights the need to integrate DHCP and DNS management with IP address planning, which I've always contended helps eliminate duplicate entry of common data, saving time and reducing the potential for data entry errors.
Another comment I found interesting is Jeff's contention that some organizations will conclude that managing two protocols, IPv4 and IPv6, is expensive, risky and difficult and will fully implement IPv6 sooner rather than later. If this prediction holds true, then the need to plan for and implement IPv6 on Internet-facing servers is even more urgent than I discussed in a prior post. IPv6 is the future! Plan on it!
Incidentally, if you're interested in more discussion regarding IPv6 allocations and even allocating address space such that assignments have "meaning" as Jeff suggests, please consult Chapter 3 of my IP Address Management Principles and Practice book.