Media is evolving (look at games, TV, youtube, and instagram). 3D will find it's place within the evolution of media.
One area where the long form exceeds the 90 min format is the depth of characterization it allows, and accompanying narrative attachment.
Soap operas have relied on this effect for years, allowing them to succeed despite low production values.
Coupled with the superior craftsmanship of modern episodic TV, is a pretty "gripping" experience.
The extended narrative structure also allows more justification for the characters actions to emerge naturally. In a shorter film, a lot of the characters' dialog has to serve as exposition, resulting in dialogue that sounds contrived.
I've also noticed shorter movies reliance on tropes to condense the timeframe of the narrative action so extremely. Things like voice-overs, montages, heavy make up to show aging, conventional narrative structures, the aforementioned expositionary dialog, (sub) titles.
The fact a narrative that spans years can be communicated effectively, in a 90 min film, is powerful evidence that the art of filmmaking does not use a visual medium to simply create an experience that relies on the verisimilitude to lived reality.
This highlights what I see as a...quirk of human inclination to try and recreate, or rather present as alternative perspectives, imagined realities.
Personally, probably related to my middle age, the prospect of technology to create virtual reality has minimal appeal.
In the other hand, technology that allows enhanced perceptions into actual reality is highly enticing, and seems to be an underserved area of human experience. I'm thinking of things, for example, like cognitive enhancing drugs. Or tools that can help control out of balance behavior.