It's too early to tell for sure whether iWork for iPad will fit the bill for most users. But it's likely that if you need to work with Word documents or their equivalent, Pages will be a fine choice. For presentations and spreadsheets, the proposition is dicier: While iWork for iPad may allow you to create visually impressive documents, you may face interoperability issues with non-iWork users.
Is Microsoft Interested in Being an iPad Developer?
If iWork isn't enough to satisfy business needs, the next logical question is whether Microsoft will deliver a solution. Microsoft has continued to update Office for Mac for decades. Typically, the Mac updates lag behind the updates to Office for Windows, but they do exist and offer both file and feature compatibility with Office for Windows users.
Microsoft, which produces few iPhone OS applications -- the Bing search utility is the only one that comes immediately to mind -- hasn't given a sign either way regarding developing for the iPad. Given that the company is busy redefining its own mobile lineup with Windows Phone 7 Series and pushing ahead with Office 2010 for both Windows and Mac (and Office 2010 Web, which I'll come back to later), it's unlikely that Microsoft wants to offer software for a new device from Apple that has UI features and guidelines that are vastly different from anything it has developed for before.
Certainly, this isn't a priority for now. But if the iPad proves itself popular, Microsoft will have an incentive to develop a version of Office for it, and possibly other apps as well. For the time being, iPad users will have to wait.
Other Office Suites for iPad
With Microsoft out of contention, is there potential for an Office-compatible suite for the iPad beyond iWork? Yes. There are already several such suites and apps available for the iPhone and iPod touch. They let you create, open/import, edit and export documents using the Office and iWork for Mac formats, along with other, less application-specific, formats like plain and rich text.
Among the handful of such offerings in the App Store, some, like MarinerCalc, provide one specific feature -- in this case, spreadsheet functionality. Two App Store suites, however, come close to being full featured Office replacements: Quickoffice Mobile Office Suite (which comes in two flavors, a basic suite that allows viewing and editing of documents for $9.99 and the premium QuickOffice Connect for $14.99) and Dataviz's Documents to Go (available in basic and premium editions for $9.99 and $14.99, respectively). Both allow you to view all major Office and iWork file formats and to create and edit (with formatted text) word processing documents and spreadsheets.
Documents to Go Premium also offers support for creating and editing Powerpoint presentations. (QuickOffice plans to offer this capability in a free update later this year.) The premium versions of both tools allow you to copy files between an iPhone or iPod touch and a computer or transfer files and collaborate using Google Docs. Quickoffice Connect also allows transfer and sharing of files through other online/cloud based services including Apple's iDisk and Drop Box.