Here's a list of places that are open and or closed as of wotlk.

[kelurn]

Why do I always see the failest of threads from people with 1-4 rep?
You basicly beg for rep now adays.

[elliotthehobo]

NONE ARE CLOSED... I can still go under stormwind and Old IF still works... Repost and common sense for explorers...

^this

filler

[andykh]

Nothing new, with some research everything here can be found, as said above there is no "Opened or closed" as everything will always be accessible appart if totalaly deleted which you can see blizz doesn't do just by taking Old IF by example - THe only thing I learned from this actually is the WAY of getting to newman's landing which looks pretty easy actually