Presently (Google's Presentation Tool)

I spent a little under 5 minutes throwing together a demo presentation of Presently, the just-publicly-launched presentation tool from Google. Give it a try here: http://docs.google.com/Present?docid=dhtt7t75_60hdjpch and let me know how it works as an audience member.

What Presently includes:
Pre-designed themes
Flexible, click-and-drag editing options in your web browser
Font and formatting controls, including highlighting

What it does not include:
The ability to export to .ppt (key for many web conferencing services)
Live collaboration - I don't think. I don't believe that anyone can highlight or annotate during the presentation, but I will have more time to test later on.
Presenter controls - all you can do is view your roster, and audience members can scroll through slides at their own pace.

A screenshot:

It was fun to work with, but I can't call it 100% useful for my presentation needs until it has greater compatibility and more live controls. Overall, a strong B-. Definitely worth a few minutes of playtime, and definitely something to keep your collaborative eye(s) on.