In these uncertain times, push systems for knowledge sharing and management are giving less results than before due to the limited planning visibility into the future - it is just becoming too hard to provide the users with the tools they need before they need it. The knowledge workers have turned to pull systems to create situational software solutions to assist in solving their business problems. Excel has always been business user's favorite tool for capturing situational solutions and managing their personal knowledge. Excel has become the most successful long-tail client in the enterprise.
For businesses to be successful, they must now cater for rapid innovation through collaborative knowledge sharing pull systems, known as Enterprise 2.0 systems (E2). Thus, having knowledge locked into personal Excel worksheets on peoples disks pose a threat to learning and innovation across a company. The same can be said about any knowledge that is not shared and findable, typically locked down by ultra traditional policies such as "need to know basis" applying by default strict access control.
Companies want to unlock all this intrinsic knowledge by using collaboration platforms, and of these SharePoint is what most organizations decide to implement (adoption rate between 55% and 80%).
So business users now face a challenge on how to move their Excel solutions into the E2 sharing and collaboration platforms. Most of them even want to enable shared information entry into worksheets, so they welcome SharePoint as the data capture tool. But how to provide the rich knowledge visualization of Excel on the web? Enter MOSS Excel Services. I recommend reading the Introduction to Excel Services and Excel Web Access article for a good introduction to ES/EWA. Also read Business Intelligence with SharePoint and Excel on TechNet Magazine for an analysis of some usage scenarios.
It might all seem simple at this point, but there are some limitations with Excel Services and multiple other options for re-implementing Excel client-side solutions functionally on the SharePoint platform. Add to the picture VBA macro infested Excel workbooks, and there is no simple migration path. In addition, the choices you make can exclude the business "super users" from being able to create situational solutions - hindering the Web 2.0 (W2) style flexibility that you aimed to provide in the first place.
A SharePoint roadmap for Excel long-tail workbooks is needed, and that is the scope of my next post.