Hello,
I've created a pull request that adds support for DNS lookups in -addnode and -connect, as I think it's a very useful feature.
Apparently it is considered a security issue by some (including satoshi, I've been told), so by default it is disabled, and the command line option -dns needs to be passed to enable it (as suggested by jgarzic)
See
https://github.com/bitcoin/bitcoin/pull/192