Large port updates

[Ivan Voras]

Is there a "best practice" for automated updating large number of 
interdependant ports? I keep my ports tree up-to-date, and sometimes I 
wish to install applications that depend on a newer version of an 
existing one, and fail.

My current example is gnome. Recently, whatever I want to install 
requires gnome2.8 - how to update the giant list of gnome libs & apps? 
portupgrade -r? (but on what package?)

What about ports that have dialog boxes which require user intervention?