You know, they're you're DVD's. I'm pretty sure you can continue to watch them in any order you want. It's not like he's in your living room, right now, with a plastic lightsaber poised over your head. Is he? Omigod...if he is, blink twice for yes, once for no...
But seriously, for new generations, certain things from the OT already have lost their importance simply because they're dated. Like Lucas points out in the ANH commentary, when the next generation watches these, the cantina isn't going to be so weird and neat because now everybody puts tons of aliens in a bar. Back when we saw it, it was a cool, relatively original concept. The next generation won't bat an eye. Emphasis will change when they're watched in chronological order, but their will still be drama. Like is Vader really trying to help Luke, or does he just want help killing the Emperor so he can be head honcho? It'll just be new emphasis that we have trouble seeing because we're used to watching it from one point of view. "Many of the truths we cling to depend greatly on our own point of view". Things one era thinks are cool, the next era may not. So for us, watching them in 456-123 is fine. Its how we experienced them, and we can continue to experience them that way. But the next generation, for the most part will see 1-6 and wil get to have THEIR OWN experience with the films. And that will add to the timelessness of star wars.