Well since some Daedric realms are inaccessible or uninhabitable, I wonder if it's possible for astral projecting (out of body travel) yourself into a Daedric realm if astral projection is even possible in the Elder Scrolls universe? I think it would useful for those who want to visit realms like for example dangerous ones Malacaths, or Molag Bol's,Vaermina, etc realms without actually physically traveling there especially talking to Daedric princes face to face (well especially useful for their worshippers although I don't know where they'll do it though maybe the Daedric princes should have their own temples in Tamerial?).

I wonder if there is a future game or DLC that would explore this idea?

It might be possible, I suppose. There's http://imperial-library.info/content/skyrim-dream-sovngarde where a soldier mentions he had a dream of being invited into Sovngarde and meeting the people there the night before he went off to battle during The Great War. "Projecting" like that into a Daedric realm would likely need some kind of permission or invitation from the Prince, but I don't otherwise see why not.

I imagine, following from what Huleed said, that a soul or a mind can be projected over vast distances as well as into other planes. I think the Psijic Monks can do this from what you see during the quests for the College in Skyrim.

There's also the incident with Peryite's followers during the oblivion crisis; It amounts to unintentional/uncontrolled/unwilling astral projection.

Oh yeah, let's have my soul floating around Clavicus Vile's realm while my body is stuck back on Nirn!

That'll end well.

The idea of someone doing this willingly to themselves is almost as stupid as I dont know, putting yourself into a suspended animation sleep right next to an out of control Skull of Corruption...
Might as well give Mehrunes Dagon the bird, tell him his mother made dishonorable offers of peace to the Aedra and then hand him the biggest axe you can find.

Lol. Someone just casts soul trap. Bam, the most epic hero in the universe died in one fell swoop.