Sramana Mitra has a post by Sujai Karampuri:
The drivers [for growth] will be-
* Decreasing cost per line
* Decreasing operating expense
* Decreasing cost of PC (or similar device)
* Social attitudes and habits embracing broadband facilities
* More Indian content
With the decreasing cost of PCs to under Rs. 10,000 and then to under Rs. 5000 soon, and with increasing in content for Indian masses, the broadband penetration will be going through a revolution, and I call it the Broadband Revolution in India. The cost per line will dramatically reduce from the current Rs. 7000-10,000 per line to around Rs. 1500-2500 per line by 2010.
The pieces of puzzle are falling into place. With advent of wireless broadband (such as WiMAX and WiFi), with decreasing costs of PC, we will see the penetration grow slow and suddenly, when the price points have achieved that critical milestone, it will take a dramatic upswing and go on an exponential path for the next few years.