The default config for named points to the root nameservers, which means several queries for each host lookup, and lots of everhead. This slows down the access, and should not be used because of the distributed design of DNS.
There's no "default config" for named. If you don't create a named.conf, it doesn't start.
The caching-nameserver package includes a configuration for that purpose. The root servers are consulted for top-level domains, and the result is cached. For common sites like Yahoo, MSN, and Google, you'll only query those once every 172800 seconds (48 hours) (try "dig yahoo.com @a.gtld-servers.net" to see the GTLD server's TTL). The number of bad queries from misconfigured MS resolvers will dwarf the number of legitimate queries from home caching servers.
