I don't own a tablet, but I am extremely thankful for their rising popularity for a number of reasons that have to do with stirring up virtual monopolies that previously existed in the computing market.
First processors - before the rise of mobile devices you basically had to buy a computer with a chip from Intel. The only other option was AMD as a real competitor, but they never broke 10% market share even in their best years. Now, tablets are made with processors from several competing companies - Qualcomm, AMD, Apple's A5 & A6 and Samsung all make their own in the market. Intel has struggled to compete because their x86 architecture is too power hungry to work well in a small portable device and they entered ARM race later than the other 4.
Second - Operating systems. Again, we for many years saw a near monopoly of Windows because no one could create a functional and easy-enough OS to compete. Linux cornered the power user market and Apple the high end hardware market, but neither were very popular. Now, thanks to Apple's iOS (in the iPhone and iPad, which has had a reciprocal effect in boosting the popularity of OSX and selling more Mac desktops and laptops) there is an entirely new market for operating systems - one in which Microsoft has floundered in for years. The main competitors are Apple and Google, but modest market share goes to Blackberry and Microsoft and the makers of Mozilla Firefox are about to release a mobile OS of their own.
People who know me should get two fundamental parts of me: I don't have unlimited faith in the free market to solve the world's problems, and I'm a huge nerd. Very often, those come in to conflict when I realize that the technology I love is generated in a free market that externalizes huge social and ecological by-products to the developing world, as when we dump our tech-waste in India or outsource the building of MacBooks to Foxconn in China where workers are pushed so hard they become suicidal. In this case, though, I find some comfort in the re-opening of previously un-competitive markets because it has a unleashed a wave of innovation in software and hardware that I haven't seen since the 90s. Seriously, it is exciting to watch today.
The one major downside to all of this is that newer computing devices tend to be non-upgradeable. You can't swap out RAM or storage chips they way you can on traditional desktops without highly specialized tools. Even then, good luck figuring out how to solder the new one in. This has even trickled into the laptop market - newer ultrabooks are so tightly engineered that you cannot modify components. I'm dreading the purchase of a new laptop this fall because I won't be able to upgrade the RAM and the hard drive they way I was able to on my current one.
