I disagree, because traditional TV sometimes presents exciting entertainment, with a classic style that became one of its superiority.
They will just have to blend. Depending on the income of the persons, some will have them both while others with less economic means will make do with TV, all the others in between - have TV and occasional on-line entertainment (like youtube).
What I am saying is that though traditional TV will not die yet, there are now other ways to access TV content. Like me, since i face computers most of the day, I cannot watch TV so I resort to using the internet to watch TV content.
Youtube old so in my opinion it will never end maybe after 15-20 years its one of the most visited sites in net and for me its best and favourite ofcourse