Google has entered into almost everything it's competitor's(Microsoft) are in.
- Google Chrome (Browser),
- Gmail (Email Engine),
- Google OS (OS),
- Android (Mobile Platform)
- Office tools (Excel, & Docs etc.).
- Google App Engine (Cloud Computing)
In my view Google Waves = Gmail + GTalk + Robots(Tools you can build) + Nice Features packaged together to ease most of the communication disabilities.
1.Real Time Collaboration
2.Natural language Tools
3.Extending Google Waves
I strongly recommend you to watch the waves presentation video to understand it better. Special thanks to Thoughtworks Geek night for an insightful community event in Chennai on Google App Engine and Google waves.