Google will soon be releasing a presentation application in its Docs & Spreadsheets lineup. This is big news and will be rounding out the office applications for Google. When this hits it will really start to challenge Microsoft Office. Yes, I know that there are many other alternatives, OpenOffice, NeoOffice, etc. but Google is a really big name and may be able to market this correctly, maybe a link at the bottom of the Google Search page, potentially taking a lot of business away from Microsoft.
Many people say that Google Docs & Spreadsheets will never challenge Microsoft Office, for most people who just need some standard word processing and spreadsheets along with some simple occasional presentations for school, it is more than enough.