At this week's CTIA Wireless 2011 conference in Orlando, tablets have taken center stage. Not only have multiple new devices been announced, but predictions have been made that tablets will ultimately replace laptops as the standard, "post-PC" workplace computer.

I don't agree. Ever since rumors of Apple's first iPad began to look credible back in 2009, I've been watching the tablet space with a mixture of wonder and confusion. After all, the devices really don't offer anything you can't get on a smartphone or a notebook computer, and their form factor is inconvenient, at best.

Yet strong sales are backing up the hype--at least for now--suggesting something about the devices has caught on with consumers.

What is that mysterious "something"? Purely marketing, I believe. Apple is nothing if not master of the glitzy sales pitch, and there's never been better proof of that than the iPad's current success.

Mark my words: The device--and all the others of its ilk that have sprung up for a piece of the action--are nothing more than a passing fad, at least in the mainstream. Here's why.

1. Limited Functionality

As far as I can tell, tablets do not offer any significant functionality that's not already available on a smartphone or notebook computer, yet they lack critical components like keyboards. In fact, you can get a laptop with considerably more memory and storage and a much better CPU for a significantly lower price, as my PCWorld colleague recently pointed out.

So why the hysteria? It's a fancy new toy, and--in the case of the iPad--one from Apple, at that. Never underestimate consumers' desire to impress each other with the latest and greatest gadget, especially if they're Apple fans. "Latest and greatest," however, doesn't tend to stay in one place for long.

2. It's Inconvenient

Unlike smartphones, the tablet form factor is too large to fit in a pocket or purse, yet it doesn't offer anywhere near the functionality of only slightly larger devices like notebooks and laptop computers. I just don't see why you'd be willing to carry one of these things around--in addition to a phone, most likely--when you could have something convenient (a single good smartphone) or powerful (a laptop).

3. Waning Excitement

It's true that other manufacturers are still hot on Apple's trail with their own iPad-like contenders, but the release of the iPad 2 made it clear that excitement with the devices is already fading. Reviews of Apple's new tablet were generally mixed, suggesting that reality is beginning to sink in.

4. Remember the PDA?

Back in the 1990s, PDAs were the must-have device du jour, but they went on to spawn today's smartphones. And indeed, the value they offered--and still offer, in smartphone form--is hard to argue with: portability, organizational tools and Internet connectivity, to name just a few. The natural evolution in this space led from something bulky but useful into something conveniently portable and useful; why would we want to go back again?

It's no secret that I am not an Apple fan, as its devices are so closed and restrictive. For that reason, I'd be far more inclined to look at Android tablets such as the Motorola Xoom--which, I should add, could certainly be useful in niche applications such as health care and inventory control.

For my purposes, though, I just can't be bothered. I see no reason to own a tablet, and fully expect them to fade out of the mainstream over the next few years.

Follow Katherine Noyes on Twitter: @Noyesk .