DNS has been around so long, that its hard to think of how it could get improved. DNS has always been one of those set-it-and-forget-it technologies, that unless you're an ISP or the host of a major zone you probably rarely think about it in your environment.

With Server 2008 come a number of improvements to DNS the majority of which are underneith the covers. All of these improve the performance and/or extend the functionality of DNS. David Tesar, in a recent blog post, talks about some of the new functionality and provides a few links to where you can get more information. He discusses DNS on Server Core and the changes to the primary read-only zone that are necessary to support read-only AD-integrated DNS. He talks about background zone loading and how this new functionality speeds the process of bringing large zones on-line. He also introduces the global names zone for single-label names (think WINS), as well as support for IPv6. Lastly, he talks about some of the updates to the DNS client that are worth reprinting below:

For Vista clients or WS08 servers, the DNS client has a few good changes:

• Periodic check to make sure the client is authenticating with a local DC (configurable via group policy). Previously, a client would only fail back to the closer DC when forced.
• Locate the nearest domain controller using the defined Active Directory sitelink costs instead of searching randomly. This is disabled by default, but good to enable when you have clients across slow site-links.
• Use link-local multicast name resolution (LLMNR), also known as multicast DNS or mDNS, to resolve names on a local network segment when a DNS server is not available.

Read his analysis along with links to detailed descriptions at: http://blogs.technet.com/extreme/archive/2008/04/25/windows-server-2008-dns-enhancement-nuggets.aspx