It's just that nobody has yet proven what the market is, or how big it might be. But nobody seems to want to take a chance that a market exists, and that Apple will stake out leadership before anybody else can mount a challenge.
That is not to discount Microsoft's historic interest in the tablet segment of the market, but simply to point out that, up to this point, the segment has not gotten much traction, perhaps because "different interfaces to the same functions" has not resonated. Microsoft's approach has been to envision a PC with a tablet design.
Apple's approach is more similar to that of the Kindle and iPad "touch," though, more a media reader and entertainment-driven Web appliance than a 'notebook with a different interface.'
The range of rumored interface, operating system and featured applications illustrates what happens when suppliers try to position a new device mid-way between smartphones and netbooks and notebooks.
Hewlett-Packard is said to be debutting a slate computer that it will offer by midyear. H.P.'s slate will have a camera and ports for add-on devices, like a mouse. Apple's iPad appears to dispense with those options.
Under the hood, the iPad is powered by what might be called a "smartphone" processor, while others likely will try to use "netbook" processors.
Google might try to power its slate using Android software, which was originally designed for mobile phones. Those hardware and software choices show some of the issues involved when trying to create a new class of devices mid-way between netbooks and smartphones.
Then there is the matter of "niche" to pursue. Apparently the first the idea was to create a device for designers and architects, but lately the company is thinking of a broader market of consumers and so would include e-books, magazines and other media content on the device.
Nokia is said to be designing an e-reader. The point is that there is so far no clear consensus about what the category is, how people will use the devices, or whether there is only one large, or multiple more specialized categories, to be satisfied. That accounts for the diverse choices about featured applications, processors and operating systems, among other choices.
All for a market that nobody knows exists, for sure.
