You may not realise it, but GIS is not just a technology; but it is built on the concept of integrating spatial thinking into everything that we do. This enables us to quantify and qualify how we live more closely, and to understand it. This is why you are seeing GIS embedded into the decision making processes of so many businesses around the world and reaching billions of people.
It is rather interesting to consider the future of GIS. Typically I do so to aid in my future employability or general usefulness at work - like learning Python and exploring new GIS software.
But a step ahead of all that is the implications of having very easy to use GIS technology available to everyone, even passively gathering useful data though ubiquitous GPS receivers now found on basically any consumer electronic device. Ignoring for the moment the massive impact on privacy - in an ideal world such data would be gathered in an entirely aggregate anonymous fashion - the possibility of harnessing crowdsourced information is stunning.
How much more accurate will traffic monitoring, supply chain management, and store spaces be? The applications of such masses of data are huge for site management and land planning as well; in addition no doubt to hundreds of other applications that we can't really begin to imagine.
One constant will be, baring a nuclear war or increasingly stupid stances that are being made on the freedom of the Internet, most of these applications will make their way online. Maybe not in browsers, perhaps to start in an open source application similar to how PDF files can be opened upon data retrieval by Adobe or Foxit or whatever else is out there.
I'd honestly write more on GIS but my current efforts are directed primarily at finishing my thesis. I eagerly await the time I will have after I finish it to read some GIS/Planning/Project Management literature.