At last Google has confirmed that they are about to add a presentation software to their Google Docs & Spreadsheets family. There were already lot of rumours going around this for sometime now.
Here is what Sam Schillace, Engineering Director has to say in his post
we want to welcome the team from Tonic Systems to Google. Tonic, which we've just acquired, is based in San Francisco and Melbourne, Australia. They have some great technology for presentation creation and document conversion, and it will be a great addition as we add presentation sharing and collaboration capabilities to Google Docs & Spreadsheets.
This feature is expected to be released in summer this year.