In Google's words:
A wave is equal parts conversation and document. People can communicate and work together with richly formatted text, photos, videos, maps, and more.
A wave is shared. Any participant can reply anywhere in the message, edit the content and add participants at any point in the process. Then playback lets anyone rewind the wave to see who said what and when.
A wave is live. With live transmission as you type, participants on a wave can have faster conversations, see edits and interact with extensions in real-time.
Google wave enables users to create a personalised information and communication portal where it is easy to: collaboratively edit documents, share photos, update your blog, check RSS feeds and update twitter, facebook etc. Developers tried to imagine what email would look like it if were invented today and have created features such as: live collaborative editing, live chat, wave playback, drag and drop attachments and natural language spell check. However, features aside, Google wave will make managing email easier by uncluttering your inbox with waves.
Imagine the possibilities of Google wave combined with iGoogle! I'll try to calm myself now and give you a scenario. I start a new wave telling my colleague about an idea I have for a project. She writes back with comments inserted into the wave and suggests we add another colleague who is then able to playback the entire wave so far. The three of us collaboratively write a project outline live in the wave and we each drag some images from our desktops into the wave for inclusion in the document. When we're happy with the outline we add our supervisor to the wave and can see her comments live when it is approved. We then upload the outline and images to our blog instantly from the wave, for comments from the wider world.
As an information professional it is important to be aware of trends in communication and this one has a huge potential to change personal information management. I look forward to seeing this new tool in action.