Hmmm, I would say that the skinny jeans trend isn't gonna last for much longer. And that's essentially what it is: a trend. Besides, I never see anyone other than emo/scene kids wearing skinny jeans.
Where do you live? Because in most of the major cities in the US and elsewhere, everyone is wearing them. Perhaps your perception that they are emo/scene makes you assume the people wearing them are as well?
I think its a joke to discuss the longevity of skinny jeans, they are not going anywhere fast. People are not going to give them up, they have changed so much about how we are able to dress. As with all things that become very trendy, those who adopted it solely as a trend will not continue to wear them, but for people who had been wearing them years before they became mainstream they will continue to be a wardrobe staple.