Nokia's N810 Tablet was too expensive and ahead of its time. And from what I can tell the device was not a commercial success (I might be wrong). But a purported successor (the "Rover") may gain traction. We're entering an era of mobile tablets, or at least a period where consumers will have lots of options for mobile IP-connected devices. There are all kinds of rumors of Apple developing a tablet and Android tablet rumors abound as well.
Mobile tablets will sit between smartphones and netbooks and may be sold like mobile phones with data contracts. This is the key: the connection.
After the demise of my Windows Mobile phone, I opted for a cheap Sanyo candy bar phone (as I await the Pre) and an iPod Touch for mobile Internet access. I have to rely on WiFi, which isn't as much of a problem as I initially thought. But the two devices are acceptable to me and I don't have to deal with the problemmatic iPhone phone.
As I wrote on Screenwerk in late 2006:
While there’s no single scenario for mobile, many people are operating under the assumption that people want an all-in-one device. Some people certainly do and will. But seeing the new Sony VAIO UX mobile PC made me think again about a “two device” world in which people use “Device A” for browsing the mobile Internet and a phone for conventional voice communication.
There’s something enormously challenging about getting the form factor right for an all-in-one device: the right-sized screen, a full keyboard, as well as a phone that works and is comfortable to use. There are probably a range of devices and mobile tablets coming (e.g., Sony Reader) that will be preferable as mobile Internet devices vs. a Treo or Blackberry. Some of them will undoubtedly be phones as well or have WiFi calling capabilities.
Tablets will be more like netbooks than smartphones in terms of the Internet experience. However tablets may bring the apps stores onto a larger screen (e.g., the rumored Apple tablet). The Nokia tablets are like big smartphones with a slide-out keyboard and will undoubtedly access the Ovi store. As an aside, it will be interesting to see how some of the next-generation tablets will address the keyboard/data entry challenge. Obviously they'll have touch screens. The Kindles for example have a physical keyboard on the device.
All these devices will also operate as phones (via Skype or equivalents). These connected, non-smartphone devices are thus something of an unanticipated "end-around" around voice fees in some sense.
I suspect within three to five years the mobile market will look like this: