Despite "Harry Potter and the Deathly Hallows" (both parts) being in full 3D, this re-release will only present the movies in 2D. "Harry Potter and the Order of the Phoenix" and "Harry Potter and the Half Blood Prince" also had select sequences presented in 3D exclusively for their initial IMAX releases. The 3D sequences have not been seen by the public since then (not even on BluRay). I thought it would have been a nice if the studio could have taken this opportunity to finish converting the series in 3D, but I suppose it wasn't meant to be. It should be noted that the Harry Potter movies were always filmed in 2D and that the 3D sequences were always just considered "bonuses" by the studio. They made the final installments 3D at the height of the 3D boom, but the effects were so underwhelming they even cancelled the 3D release for 'Deathly Hallows - Part 1' (though they did eventually release it on BluRay 3D).
At the moment I have other thoughts about this marathon than you might expect. I'm wondering how the films are going to be spread out though the week? What is going to happen to any new releases currently in IMAX? Will people be able to see all the movies? Will that lead to some complaints? I suppose this will push Terrence Mallick's "Voyage of Time" out of most theaters. Re-releases of classic movies in the IMAX format is nothing new (see "Raiders of the Lost Arc" "Titanic" and "Forest Gump" [strangely enough]), but never have we seen one that requires so many hours and show times to properly present. Part of me is excited to see such a major event for classic movies in IMAX... however, part of me is also cautious that this isn't exactly going to be a problem free release.
Ah well, this should be fun none-the-less. The marathon starts on October 13th and is scheduled to run for a week. If it is successful and complaints come in from people that one week isn't long enough to see all movies (which is very possible), I think ""Jack Reacher: Never Go Back" may have to give up his spot (or most of his showings at the very least). I suppose we'll cross that bridge when we get there though.