Time will test the temper of the material that Star Wars is made off. The original is a classic and will be remember as so. No mater how much Lucas alters it, the fact remains that the extra scenes were not there for 20 years. If taught in a film class, the originals have to be used because it would be a lie if taught otherwise. Hell, even a reference to it from the 70's and 80's will have to have original scenes, otherwise it wouldn't make sense. The death star explosion did not have a ring around it in 1977. You can't show a scene like that say on "That 70's Show." You have to show the original.
There are too many film purists out there, us included, that won't let this die. I myself am only 23 and don't plan on dieing any time soon. So if you say that this is the last generation, well, techincally there have only been 2 generations so far. By the time I'm 80, hopefully there will be more generations that loved the originals as much as me.
You can already see that there is very little love for Episode I, by fans and the mass public. Episode II has hardly any mention anymore and given that Episode III is fairly new, I'll say it will die out with time just like first two. What holds the test of time? Well, ESB for one. That movie sustained the least amount of changes and is reguarded as most fans favorite. That thing is bullet proof.
We are not the LAST generation. We are the FIRST. And it won't die with us.