web based google client will enable the users to connect to the google talk server without requiring to install the client on their computers and also witout caring about the platform they are working on.

There are so many others why another?

First answer is I don't care if it is already done. If people stop doing things only because,it is already done we would not be able to see the remarkable innovations and inventions around.
second reason is that it is a student project and students are required to prove their acquired knowledge and skills by development something cool in limited time with all other workload intact