Or, perhaps a better question, is it the Nerevarine's responsability? And would s/he realise it?

See, the Nerevarine was only put on the bus, and if you play the same character all the way through the games not even that. If you plan on playing through to Skyrim as the Nerevarine then your going to have to deal with the fate of Morrownd (emotionally), after abandoning it to become the Champion of Cyrodiil. I'm struggling with this right now, as the prophecies in Morrowind that don't make immediate sense are going to suddenly make horrifying sense several decades later.

In the end, Dagoth Ur had to be killed, for the sake of all Tamariel. From what little i've gleaned from an incomplete playthrough the Nerevarne does learn that it is only the power of the Tribunal keeping the MoT up. They even deal with it for a time when Vivec 'disappears'. However, Dagoth Ur cannot be ignored, and the problems that will come will have to be dealt with. Can the (partial) fault of what hapens ever be placed at the Nerevarine's door? Even if given the full knowledge of what would come to pass, saving Tamariel at the cost of Morrowind decades later is arguably a no-brainer. We'll leave the Argonians out of it, since they are a seized oppertunity rather than a direct result.

It doesn't stop the emotional fallout; my Nerevarine 'spent' a decade as a warlord on the fringes of Black Marsh, avenging her slain people in her grief over what happened. She'll be 'better' by Skyrim. =P

However, I really would like others peoples thoughts and to go deeper on the implication of all that happened with Morrowind and what we learned in Infernal City, but on a 'personal' perspective of the Nerevarine rather than a historical of cultural or even racial perspective. The person. Because barring violence the Nerevarine has a looong time to watch the Dunmer change. We as players have a great deal of involvement with Morrowind and are even involved with the crises itself, yet most of the conversations about this are from a detatched and historical standpont, rather than from the point of view that arguably the main player is still alive somewhere and was under the players control. At some point, whether in Akavir or if it was just a rumor, they are going to potentially return of hear of whats happened in the abscence. Some might not even have left at all.

Doubtful, the Tribunal was losing power anyway, because they did not use the Heart's power in accordance to its evil. The Ministry of Truth would impact sooner or later.

Yes and No. The Nerevarine ended up being a total tool. The Mythic Dawn, Uriel Septim, Azura, Vivec, and Lorkhan all seem to have manipulated events to have a Nerevarine rise to prominence and destroy the Heart of Lorkhan. Rise a Nerevarine did, and they executed their role perfectly. Unknown to the Nerevarine were the consequences of his/her actions. Perhaps we could blame the Nerevarine. But, in the end, did Nerevar's reincarnation really have a choice in the matter?

The Mythic Dawn was involved? How?

I blame MK. Could Vivec have disposed of it somehow, before he disappeared or died?

While the above poster is correct- I've never seen a mention of the Mythic Dawn prior to Oblivion- I think the Nerevarine's actions WERE motivated by necessity.

If the Nerevarine doesn't rise, if he DOESN'T destroy the Heart, Dagoth Ur wins, and he spreads Corprus Disease and blight storms throughout all of Tamriel, the continent is destroyed. Morrowind's destruction was pretty much a foregone conclusion- the Nerevarine only changed the method and the overall scope.

I think the reason the poster mentioned the Mythic Dawn is without the events of Morrowind disabling a Tower (In this case, the Heart of Lorkhan and Kagrenac's enchantments rooting it in place), the veil between Oblivion and Mundus would have been too strong for Dagon's invasion to work. Yet clearly the Mythic Dawn was formed before that Tower was ever disabled.

While there's nothing at all in the way of evidence that shows their involement (Indeed, I don't think there was any direct involvement on their part), it implies that at least they knew that something was going to enable their plans to come to fruition. In truth, I simply think it points to Mehrunes Dagon being far less stupid and far less short sighted than most people give him credit.

Just referring to the http://www.imperial-library.info/content/nu-mantia-intercept in which Nu-Hatta claims that the destruction of the Heart of Lorkhan (First Stone) was a bad thing for the Empire, and that the Empire was "tricked" into sending [the prisoner to become] the Nerevarine by "Dagonites".

Whether or not Nu-Hatta's accusation is justified hasn't been confirmed, though.

If Dagoth Ur hadn't been stopped, he would have grown in power and finished Akulakhan, gaining the means to conquer Tamriel. I doubt Nu-Hatta was aware that Dagoth Ur was building a second Numidium, or that his long-term plans did not stop at conquering Morrowind.

In the end, the Dagonites were still thwarted, and Landfall would have likely happened regardless of the Nerevarine's actions.