This.. DH are not supposed to get metamorphosis.Y'know, I was watching the WotLK trailer there, and I said to myself: "Hey, that's not the Lich King's voice from the actual game..." and for a moment I thought they changed voice actors mid-way production, but then, near the end of the trailer, the voice slowly changes to the Lich King voice we all know.
But more OT: In the off-chance we do get Demon Hunters as a playable class, I am almost certain they will not be based on Illidan. Illidan today (or, more specifically, back in TBC) is a demon. No longer a Night Elf, but a demon, with more powers than a DH should have thanks to his now corrupted blood.
If we get a DH, it'll most likely be the Demon Hunter 'concept' from the Warcraft 3 campaign. In other words: without 'Metamorphosis', since said ability was only 'granted' to Illidan when he consumed the Skull of Gul'dan's power and got his body permanently changed into the half-demon, half-night-elf form he is known today, meaning DHs are not supposed to have such an ability.