A Tool for Content
As others have noted, the iPad is best treated as a tool for consuming content, rather than creating it. That's reflected in the versions of Apple's iWork applications that the iPad can run; although they offer some very basic functions, for anything beyond some very simple data entry and formatting, documents have to be moved to a computer with a "real" presentation, spreadsheet or word processor. Although the iPad can run most applications that were designed for the iPhone, it's not a terribly satisfying experience. The default presentation for these is at the same resolution of the iPhone, but one can enable an enlarged view of 2x, which takes away all the smoothness of the original app's design. The only advantage I can see to this is that a mildly nearsighted person might find this preferable to digging out a pair of reading glasses.
As one might expect, the iPad can be managed in a business environment using the same tools that Apple provides for the iPhone. The free iPhone Configuration Utility covers both devices, and can be installed on machines running Mac OS X or Windows. Although the manageability of both devices is expected to improve upon the forthcoming release of iPhone OS 4.0, the tools that currently exist are straightforward and cover a good deal of IT's concerns. With the configuration utility, one can set up provisioning profiles for cellular carriers, WiFi networks and VPN access. It's also possible to configure e-mail access to POP- and IMAP-based services, CalDAV-based calendar servers, and updated Microsoft Exchange 2007 servers. Exchange sees iPhone OS clients as if they were ActiveSync devices, and this allows IT managers to remotely wipe lost or missing devices from within Exchange. "Wiping" in this case is a bit of a misnomer; what actually happens for the more recent devices is that the data encryption key is securely erased, making the data unrecoverable by conventional means. When I tested the wiping feature, it took just a few seconds from the time I activated the wiping to its execution on the iPad; the connection was over a local wireless network, but would be equally effective over a wide area connection, being delivered by e-mail. There's no guesswork to this; once the remote device is neutralized, an e-mail message confirming the wipe is sent to the administrator, along with instructions on how to reconnect the device if it is found. Perhaps the easiest way to back up data on the iPad is to use iTunes; restoring data including system configuration and user data took just a few minutes following the wiping tests. Because Exchange's ActiveSync offers some duplication of the policies that cover features such as passcode requirements, managed iPhone OS devices are configured with a merged set of policies. The more stringent requirements are applied to the managed devices, no matter whether those come from ActiveSync or from Apple's configuration tools. Finally, the iPhone Configuration Utility can be used to centrally manage access to applications and content, and bar connections to "explicit" media. Devices can also be individually set up with these barriers, as a form of parental control. In all, the iPad is a pretty amazing device, packing a lot of punch into a slab that's no heavier than most of the books I own. Although nobody sane would recommend the iPad as a general-purpose device, it is already making inroads into business use, and with the expanding pool of applications, its usefulness increases with every week. But by promising an updated OS in a few months, and by leaving out features such as a camera, Apple's already raised the bar on itself.
Applications that are designed specifically for iPad offer users a much more appealing visual presentation, and as I noted above, their number will increase with time.