I haven't heard anything definite about this type of thing yet, but it would be a great opportunity, even if it isn't a "lead-in" thing and is done at some point after a few weeks have gone by and "Generic Lindsay Lohan Film Number 274" has taken over the number one spot due to the rapidly declining ability of a section of the populace to discern when Hollywood has run out of ideas.
(I mean, really, did we need
a "hip" and updated version of "Herbie" just so we can see Lindsay Lohan jiggle around on screen for 90 minutes? It seems she's doing that well enough on her own these days...)
Anyway, I would love to see them do a prequel marathon and I'll go one step further and say how cool it would be to do an all-day Saga marathon on the big screen. Start at around noon or so, and the final destruction of the second Death Star would occur right at midnight. Of course, this would have to be timed out perfectly, but I would imagine it could be done.
I can see it now though...Comic Shop Guy harassing the people at the theater because he only wants to see the last three films, thus "qualifying" him for a half-price ticket.
Maybe I'll just watch Episodes I and II at home, drive to see III in the theater, and come home and watch IV, V, and VI on DVD. At least at home my feet don't stick to the floor (most of the time, anyway) and I don't have to deal with rude people who need to have their cell phones forcibly inserted into their anuses.