Today Microsoft starts shipping Office for iPad, finally plugging the gap in its portfolio that’s been filled by popular document viewers and editors like QuickOffice and SlideShark.
Does this come too late for Microsoft?
As much as naysayers like to proclaim Office is dying, people still overwhelmingly use it at home and at work. Office is supported at virtually every organization. Our survey of Forrester clients at the end of last year showed strong strides by Google Docs with 13% of firms using it.* However, the caveat is companies that have gone Google are using Docs to complement Office with collaboration features and mobile support, not to replace it.
You could argue how much incremental revenue Microsoft lost out on, but I don’t think the lack of native Office apps has caused Microsoft to cede ground to other office productivity suites on the PC, where the vast majority of content is still created. Keep in mind that out of the 20% of information workers in North America and Europe that use a tablet for work, 60% of them use some office productivity software on it.** Half of tablets used for work are iPads. So immediately just 6% of information workers will be considering the Office apps as an alternative to what they are using on their tablets today. 
Is Microsoft really multi-platform now?
Releasing the reimagined "touch-first” version of Office on iOS before Windows 8 is Microsoft’s strongest pronouncement of multi-platform support yet. Yes, Outlook, OneNote, OneDrive, Lync, and Yammer were already available cross-platform, but Office was the glaring hole in the lineup. This looks like an about-face on the “Windows first and best” party line and means Windows Phone and Surface will have to stand on their own two feet without Office to help them fight their battles.
Does Office for iPad deliver what people need to be productive on tablets?
Office for iPad delivers most but not everything people do in Office. What people really need on tablets to be productive is up for debate. Design features like the custom Excel keyboard, however, show real consideration into the Office experience for touch. Office for iPad supports simultaneous co-editing, track changes, and most importantly file fidelity so your Office documents render the same way on all devices. Unlike some approaches to accessing Office on the iPad, these apps let you work on content offline.
The most limitations are in Excel, which doesn't support macros, and which shows, but does not let you create new pivot tables. It will apply existing, but not let you define new conditional formatting. The Word app will render, but not let you create new SmartArt. This follows a similar paradigm to the web apps.
Is there still a place for alternative apps?
Yes, because editing using Office for iPad — like the smartphone apps for iOS — is only available to Office 365 subscribers. Viewing, however, is free, including the ability to present using the PowerPoint app. 
Our survey of Forrester clients at the end of last year showed 14% were using Office 365. Most information workers — even those with iPads — won't yet be able to edit documents on their tablets. 
The bottom line
Office for iPad delivers functionality and design in between the stripped down alternatives and the full-featured (and latency challenged) remote desktop approaches, and is the best office productivity experience on iPads today. 
This is an important milestone that goes a long way in demonstrating Microsoft’s commitment to multi-platform support. 
And rather than this release look like a defensive ‘better late than never’ move, it actually provides a strong incentive for more organizations to consider Office 365. 
However, most iPad users will only be able to view and not edit their files using the apps today. If they can’t get Office 365 from their company perhaps more mobile power users will opt to pay $7 a month for Office 365 personal themselves. 
* data from Q3 2013 Global Productivity Suite Online Survey to 155 IT decision-makers with influence over productivity toolkit decisions
** data from the Forrsights Workforce Software Survey, Q4 2013 of 4,827 information workers in North America and Europe