A place for both
The important change in what's happening to computer use in the enterprise is that -- as my esteemed opponent eloquently puts it -- "As smartphones and tablets get more powerful, they are eroding a domain that was previously under the control of the PC, and this is hitting the PC OEMs hard."
Having debated this topic, there's a place for both smartphones and tablets as devices that help someone get their job done. This will always be, for the foreseeable future at least, alongside the PC as the PC will always be needed for focussed work.
What smartphones and tablets let us do is crack out a simple, easy to use device, wherever and "whenever" we are and handle that little job, or get that small piece of information, in a way that's empowering, comfortable, and satisfying.
Smartphones, where the real action is
Convergence is the path that all consumer electronics take, going from specialist devices (such as MP3 players, digital cameras, and in-car GPS receivers) to jack-of-all-trade devices that can carry out a myriad of tasks. And the king of the convergence devices is the smartphone.
The smartphone is king because it combines portability with the power to get work done. Sure, a PC or a notebook, or even a tablet is nice to have, but the best tool for any job is the tool you have on you.
And if you own a smartphone, I'll bet that it's rarely more than an arm's length away from you.
Also, the arbitrary line between smartphones and tablets is blurring. Samsung's Mega has a 6.3-inch screen, making it only a little bit smaller than the Nexus 7, a device that you can certainly do real work on.
Smartphones is where the real action is at.