It will be a while before that comes to pass. There aren't any significant competitors to Excel, Active Directory, or Exchange.
Can you name one, good alternative to Active Directory and Exchange that runs on a Unix platform?
As someone that spent almost a year trying to find an answer to that question I can tell you that there isn't one. These are the areas where Microsoft is still above and beyond anything else out there.
Oh and one other thing: Modifying columns/rows is consistant over all iWorks applications: Alt + arrow-keys let's you insert rows/columns above, below, to the right or left. MS Office's inconsistency and lack of hotkeys for such an essential feature makes me rage every time I use it.
Numbers sure has shortcomings though: no pivot tables, very limited scripting support, limited filtering / data manipulation. That's why I look at it as a very good spreadsheet tool, but not a data analysis tool - that's when Excel and/or Matlab come into play.