(The first Photoshop splash screen)
Did you know that Photoshop was released in 1990 for the Mac? It was written by two brothers, Thomas and John Knoll. They demoed the software to Apple and Adobe but Adobe was the one who decided to distribute it.
Computers really are incredible. A tool initially built by one guy and his brother has come to touch almost every life on this planet. If something is visual, there is a good change something in that image touched Photoshop.
This article about the history of Photoshop really shows how far the program has come. The fact is, I remember using version 4.0 of Photoshop. Which came out in 1996. I remember thinking that this program was the coolest thing ever.
Moving forward, it is exciting to think of the possibilities of where Photoshop can go. I think the system will continue to get faster (although maybe this can be attributed to computers getting faster) and complex operations will continue to be boiled down into "brushes". Healing a bad patch on an image used to require some skills and knowhow. This was packed up into a brush that makes it easy to get 80% of the job done with limited skills or training. I think other processes and "skills" will be packaged into brushes or processes making Photoshop increasingly easy to use for the common computer user.