Created attachment 600729 [details] [diff] [review]
We didn't do this for Firefox 4 since it was too close to the release. We can revisit this now, especially since bug 665580 landed in the meantime.
I propose that we tie this to the existing browser.urlbar.trimURLs pref, since it's probably the same set of users who would want to disable this.
Comment on attachment 600729 [details] [diff] [review]
Makes sense to me.