Part of the rumor is that it will go to a digital projection system. They haven't done this yet because the technology to project at a high enough resolution hasn't been there yet. Soarin' is essentially an IMAX film, projected onto a domed screen at an angle (it used to be called "Omnimax", now the format is called "IMAX Dome"). IMAX's 70mm film has a VERY high effective resolution - somewhere around 12k I believe. Most projection systems are only just passing the 4k mark. Blow that up to an IMAX screen and it can be noticeable.
The so-called "Digital IMAX" was actually a smaller resolution and was not projected at the full size of IMAX screens.
IMAX has been working on new digital projectors, that they are just beginning to roll out this year. I believe they are actually using a dual projector system to get the resolution high enough. How easily this will be adapted to a domed system (the images on film are distorted, and then it is projected through a special distortion lens to "correct" it on the screen, to correct from the projection angle), and then to Soarin', will decide what they do with Soarin'. But once done, they can do all sorts of things - like make it a variable ride experience like Star Tours: The Adventure Continues...
That's why I've been predicting for about a year it would be at least 2014 before they switched Soarin' to digital projection.