Basically meaning the main device people use to do simple tasks as surfing the web, playing a mobile game, checking bank statement, writing product reviews, and emailing?
Yes, I believe that the iPad (and tablets in general) will have a future.
Personal computers have evolved since the days of kits and hobby computers of the 70's. With the introduction of PC-DOS and the IBM PC, things became more standardized, allowing developers to focus on one platform with a business focus.
With the advent of Windows, general computing was given a pretty face. But the underlying architecture was overkill for the average consumer. It was still driven by business needs. There were so many subsystems within Windows geared toward the enterprise, that it made Windows more complicated, convoluted, and unstable than it needed to be.
Laptops/Notebooks made the experience portable. But the same overkill applied.
The introduction of netbooks, by their limited nature, caused manufacturers to start thinking about streamlining and stripping things down.
The return of tablets with the iPad (first wave was the late 90's/early 2000's), was the successful result of that streamlining and rethinking. Chromebooks were an alternate attempt to streamline the experience.
As it stands now, the range of devices needed is far wider than ever before. It's pretty much a bell-curve. There is little need for limited function devices like dumb phones, but there is also lesser need for the ultimate high end systems. (there are those who simply want the most powerful devices available but that is not what I'm referring to)
The current crop of iPhones and iPads are serving the beefy part of that bell curve well.
The question will be if and how far will Apple push the iPad toward the upper portion of that curve.