[citation][nom]nevertell[/nom]I'd rather stick with open office.[/citation]
For word processing and basic spreadsheets i can mostly agree. For highly complex excel documents, nope. For presentation, not quite as impressive (although Apple's keynote blows PPT away). Access is easily replaced by other apps, but not if you need integration with other software/people. Visio can't be replaced, nor can project, and full native SharePoint integration alone is worth the cost of office vs free alternatives to most companies that use project teams for any efforts. Outlook's Exchange integration is simply bettter than any competing offering. Also native integration with SCCM deployment tools and Microsoft monitoring solutions, rights management, and more, very important.
generic home users, sure freeware alternatives work. True business application use, sorry, Microsoft costs more, but everything else gets cheaper and more productive using it well in excess of the cost.