I just spoke to a Airtel Sales Manager of Chennai. As per him, the doublespeed is on pipeline and it would happen in another couple of weeks or a months time. He said the process is already on and its happening in a phases wise manner across various circles.
Once done, there would not be anymore 256kbps, speeds would start from 512kbps only.
We are all waiting for this change now.
Members, please keep posting if your speed is getting doubled (Free of cost)
Mention : Date,Circle and Current Speed
We can probably track the progress across various circles.