First, the bad news: No, Google is not announcing a business wiki or presentation product at the Office 2.0 conference. However, I did get a demo of a few new features in Google's spreadsheet.
First, there's a new autofill function. If you enter a series of consecutive numbers, it will extend the series. OK, yawn. But, using data provided by the old Google Sets experiment, the spreadsheet will automatically fill in a row or column with items it thinks match your selection if they're not in an obvious sequence. For example, highlight a name of a state, press Ctrl (on a PC) and drag down a few cells, and the spreadsheet will fill in other states. You can also try a state of mind (e.g., "happy") to get other emotions. Or names. The more items you select before you control-drag, the more likely Google is to fill in items you expect, as opposed to wild guesses.
Second, you can now pull in data from other sources, including RSS feeds. (For instructons, see this Google Help page.) This means the Google spreadsheets can now be real-time, for any data that's expressed in an RSS feed. Previously, you could look up certain real-time data, like stock prices, but this is much more flexible.
There's another important feature that launched a few weeks ago: If you're collaborating with someone on a Google spreadsheet, cells that other people are working on are color-coded by user. When someone starts to edit a cell, it will get grayed out so you don't collide with their edits. You can also follow a user as they read and edit a spreadsheet. This is a feature I've been waiting for. It's great for collaboration and training.