"Bookmarks > Organize Bookmarks" has been renamed to "Show All Bookmarks" in Firefox 4.

That's a stupid name change. The name no longer implies that you can edit your book marks. I recommend that the name be changed back to organize bookmarks.

Hmm... who decided to rename from "organise" to "show"? Not the same thing; not in English anyway. Poor choice.

It was done to make both the already present Show All History and Show All Bookmarks use the same wording.

You see all the Bookmarks in the Library. There is now an entry in the Bookmarks Menu button pop-up and via Firefox > Bookmarks menu to see the Unsorted bookmarks and clicking that link opens that folder in the bookmarks manager.