Here’s a useful outline of the main features of Google Wave. In essence it’s “a real-time communication platform” which “combines aspects of email, instant messaging, wikis, web chat, social networking, and project management to build one elegant, in-browser communication client”.

Main features:

Real-time: In most instances, you can see what someone else is typing, character-by-character.

Embeddability: Waves can be embedded on any blog or website.

Applications and Extensions: Just like a FacebookFacebook reviewsFacebook reviews application or an iGoogle gadget, developers can build their own apps within waves. They can be anything from bots to complex real-time games.

Wiki functionality: Anything written within a Google Wave can be edited by anyone else, because all conversations within the platform are shared. Thus, you can correct information, append information, or add your own commentary within a developing conversation.

Open source: The Google Wave code will be open source, to foster innovation and adoption amongst developers.

Playback: You can playback any part of the wave to see what was said.

Natural language: Google Wave can autocorrect your spelling, even going as far as knowing the difference between similar words, like “been” and “bean.” It can also auto-translate on-the-fly.

Drag-and-drop file sharing: No attachments; just drag your file and drop it inside Google Wave and everyone will have access.

While these are only a few of the many features of Google Wave, it’s easy to see why people are extremely excited.