Google Wave is going to change how we collaborate and work. The communication tool aspires to redefine not only email, but the entire web. You can read everything about Google Wave here and here.

What I found interesting is - what is the key difference it brings in ?

In the current model of working, when individual sends out email to people, the email gets stored in people’s mail boxes (email folders). So everybody gets a copy of the mail. Subsequent replies are also routed to everyone mail box. The email client will try to group the email based on the subject as one conversation. Using the conversation mode, one can go through the mail chain to find out what happened. 

In this model, we usually face 2 main issues