Aside from some language and performance improvements, Microsoft's web versions of its Office Apps haven't seen massive changes since their launch last year. That changed a little over the weekend, with the Excel spreadsheet app adding direct printing from within the app and a number of right-click editing options.
Other enhancements include a merge cells function and general performance improvements. Microsoft's stated position is that the free Excel versions won't replicate all the features in the paid Office product, but it's good to see some extra features getting added.
Excel Web Apps Releases New Features [Excel Blog]