One example of a page that behaves badly when browser.link.open_newwindow.restriction is set to 2 is http://weblogs.mozillazine.org/asa/. The trackback links open in a new window for no good reason, and they have width+height set. That's not completely Asa's fault; it's part of the default Movable Type template set.
== More comments from Beltzner ==
I don't know if that's for "no good reason"; the default MT templates for trackback actually look like the templates for comments. Asa's modified that slightly so it doesn't seem as sensible in its own window.