These lightweight versions of the applications will enable various users to access and edit the information from anywhere in the world through an internet connection.
You can see previews to the changes being made in the upcoming Office Suite by visiting the official information page from Microsoft.
In line with Google Docs, the Office Web Apps shall be free to use for those with a Microsoft Live login (all 400 million or so of them!). Other users shall be able to purchase subscriptions to the service as well.
To coincide with this announcement, Microsoft have created a movie-style trailer for "Office 2010 - The Movie" which directs viewers to a website that gives them a "Backstage" look at the development of Microsoft Office 2010.
I have seen a number of spoof action videos on YouTube that use Microsoft Office as the source of the problem, so I was not expecting for this video to be particularly original or funny. However, provide the concept with a bigger budget to give the trailer a true movie feel (minus any acting ability), and it actually works very well.
See for yourself:
Office 2010 - The Movie