I've spent the day at Microsoft's unveiling of Office 2013 at the Metreon in San Francisco. This product has been years in the making. It was conceived before the iPad hit the shelves, and its improvements are largely PC-focused--Excel, Word, and PowerPoint deliver richer and more fully-featured experiences on the PC than ever before. It's a product that has adapted to the multi-device lifestyle, with user-based subscription pricing (Office 365) and cloud-streamed Web apps (Office on Demand)--but the PC is still the star, and tablets are an afterthought. Office does have a mobile strategy, but that's explicitly not the focus of this event today. Even Microsoft's own Windows 8 platform won't get native Metro apps for all the Office programs at launch. (The version of Office that will be available for Windows 8 and Windows RT at launch is touch-optimized but won't use the Metro UI, except for Lync and OneNote, which will be native "Windows 8-style" apps.)
Office is a $20 billion business, and Office 2013 is the best version of Office yet. It will sell millions of licenses to consumers and enterprises (Office 2010 has sold more than 100 million copies, and that doesn't include the millions of users who use pirated versions of Office). But products at the peak of their success can still be vulnerable to disruption, and Office 2013 certainly is, especially to competitors who put mobile first, and who deliver less-good experiences for cheap or free.