Google has announced its much anticipated Powerpoint competitor. It has been added to Google Docs - the new, simpler name for "Google Docs & Spreadsheets". With the new Presentations feature, users can create "simple web-based presentations". A quick glance at the functionality shows it is similar to the other Google Docs features (word processing and spreadsheets) - with sharing, revisions, etc.
Below is a video which shows Presentations in action: