Yes it is still accessible, if you are lucky and know a warlock who can do it (as I was), you can have them get into the crypt. After that you can go to the gate (where both of you can see each other) and pull up a summoning port. VOILA! Access to all without having to try and do the auto unstuck.

I found a trick on Youtube of getting in that anyone can use (obviously I shan't repeat it here) and I went in twice a couple of months ago to get an excellent collection of screenshots. Such an amazing, and, quite frankly, stunning place, it's such a tragic disappointment that it is not offically implemented into the game, and it's still a mystery as to what it was supposed to be. Me and my friend had a bit of fun trying to work out where bosses would be placed if it had been planned as an instance.
http://i604.photobucket.com/albums/tt125/kerilin2009/skullmountain.png
http://i604.photobucket.com/albums/tt125/kerilin2009/upsidedownsinners.png
http://i604.photobucket.com/albums/tt125/kerilin2009/tombs.png The sound that those crypt gates and doors make upon being opened is unlike any other door-opening noise in the game. It's so very atmospheric, and really, really, quite creepy :P

Just went there and took a look around using WoW Map Viewer...holy crap! Yeah, I can see why they sealed it off. Teen rating? That would have been hotly disputed by the ratings board with this one, I think. Still, it seems weird that there's this whole big area (and it's HUGE) that they couldn't have just revamped and opened up instead of letting it just...sit there.

@Tokkar

Blizzard has alot of different locations that were once something, and now are nothing. Old Ironforge is one that comes to mind instantly, apparently once accesible from the throne room of Ironforge. There were video's of it on Youtube. Then there's the portal in Stormwind, that looks like the entrance to an instance.... Once again, long abandoned. (Come to think of it, it might have gone poof with the addition of Stormwind Harbor.) I have suspicions that the airport above Ironforge might have been accessible once. There's a cave that looks like it might have had an exit from there to another location. That last is just my suspicion.

I can confirm that this place is still around. After seeing this post I went to check it out.

Its scary. I agree that its the creepiest place on WoW. I can see why they closed it. o_o But .... cool to go and run around. :)

@ HunterFromTheStart

There are a lot of places that used to be accessible using a technique called "wall jumping". It used to be possible to jump forward and land on a near vertical surface without sliding down (you had to jump forward without moving once you landed) Blizz has since "fixed" this. I personally used this to access the places you mentioned and more (I actually used eyes of the beast to get into both Old IF and under SW where the portal is). It will be interesting to see how places like IF airport change with the addition of flying mounts.

@hunterfromthestart... Old Ironforge is still in the game. my shammy used FarSight and after enough jiggering got to "see" through the vault and walk down the ramp. (I know... I am not supposed to go there, but I figure, I am not exploiting anything, just looking)

Absolutely fabulous scenery, but clearly they were not ready to add it to the story. As a dwarf main, I have been itching to see what is planned down there.