I just came across a nice article about SharePoint on CRN.
They did a good job summarizing the Excel Services that are part of the MOSS server
"Users can now publish interactive spreadsheets with Excel 2007 right into SharePoint, so the tool plays a key role in the creation of business intelligence portals. For instance, users can change views with Excel output by drilling down right from a portal page by using Microsoft Internet Explorer or Mozilla Firefox. No local installation of Office is necessary. Local Excel installation is only required when editing spreadsheets. "
As a founding member of the original Web Part team here is my favorite quote:
"Microsoft has done a great job simplifying the publishing process and added many new development capabilities. Solution providers, for instance, can now build on top of a large number of filter lists. Filters are Web Parts that automate mundane tasks. "
The article misses all of the good integration to make Access and Outlook consume and use list data. Access does a nice job providing the ability to combine lists, build great printed reports and take any list data offline. Outlook does a great job surfacing list RSS feeds, mapping event list data to calendars, surfacing tasks in the new task window, and surfacing contacts in the outlook contacts UI. We both use the new GetListItemsSinceToken to minimize traffic on the server and provide richer Offline scenarios.