The Google Wave product (available as a developer preview) is the web application people will use to access and edit waves. It's an HTML 5 app, built on Google Web Toolkit. It includes a rich text editor and other functions like desktop drag-and-drop (which, for example, lets you drag a set of photos right into a wave).
* Google Wave can also be considered a platform with a rich set of open APIs that allow developers to embed waves in other web services, and to build new extensions that work inside waves.
Google I/O is a developer gathering focused on pushing the boundaries of web applications using Google and open web technologies.
Google I/O offers 80+ sessions [go to this link to get to online session info] that present highly technical content on Android, Chrome, App Engine, Google Web Toolkit, AJAX and many more.