the biggest day in Star Wars history
ESB original theatrical version isn't being re-released in December.
While the ESB original was huge, I wouldn't discount the possibility that the debut of the new trilogy smashes more than a few records.
In fact, I'll be legitimately dumbfounded if it isn't the single biggest opening weekend ever, even adjusted for inflation.
With that said, the debut of ESB is truly what forever cemented Star Wars into popular culture. ANH was already a phenomenon, and yet Empire somehow took that to another level. Even if (hopefully a likely if) TFA is a smash success and causes a resurgence in the franchise we haven't seen since ever, nothing will take away from what ESB accomplished. But if Force Awakens can bring us back up from the doldrums of the prequel trilogy (even if I personally still enjoy AotC and RotS), that'll be fine in my book.