It was announced late last night that Lucasfilm are pushing back the release date of Star Wars: Episode VIII from its May 26th, 2017 release date to December 15th of the same year.
Essentially, Episode VIII traded places with another Disney release, Pirates Of The Caribbean: Dead Men Tell No Tales. This, naturally, has sent the rumour mill into overdrive. We know that Episode VIII has already entered production, with early shoots taking place on Ceann Sibeal and Skellig Michael. However, it's unlikely that there are any script issues with it as both legendary screenwriter Lawrence Kasdan and co-writer / director JJ Abrams have both praised the script publicly.
The same, however, can't be said for Star Wars: Rogue One, which apparently had Christopher McQuarrie brought in to do some pretty hefty rewrites. Most likely, the reason behind Episode VIII's release date is something along the lines of a nice buffer zone between post-production and release date.
JJ Abrams mentioned during the run-up to The Force Awakens that he could have released the film much sooner than its original date, but used the extra time to fine-tune the finished product. That could very well be the case here, as this will be the first major studio production that director Rian Johnson has ever worked on.
There's also the fact that Episode VIII will most likely block-book IMAX screens across the globe, as well. In Dublin alone, the IMAX screen at Cineworld was booked out from December 17th until well into January. While there aren't a raft of IMAX releases in mid-January, they're more likely to run into other IMAX-friendly films in the summer than they are in the winter.
Meanwhile, there's also word that - finally - a title will be revealed along with confirmation on some of the new castmembers, including Benicio Del Toro's as-yet unidentified villain. The early word is that a Rogue One trailer will be attached to Captain America: Civil War, due for release on April 29th with the title reveal for Episode VIII probably before then.