All well and good, India is going to develop ICBM soon, the results of this particular test notwithstanding.
South Asia being nuclearized and missilized, in my view contrary to popular opinion is the best thing for stability in the region. With warhead tipped missiles, available abundantly to India, Pakistan, China it ensures that there can't be any real war between these countries, apart from some possible skirmishes like Kargil. With the keywords being nuclear deterrence of MAD.
Stability being an essential component of growth and development, I think the region is headed for unprecedented growth in the next few decades, for all, provided Pakistan can get it's act together vis a vis their internal extremist elements and provide good investment opportunities for the international community, like China has already done and India is about to do so.
As long as the you launch at me, I launch at you doctrine is in play, missiles being the most reliable way to deliver warheads, the current status quo would be preserved. The next sea change in the power equation in south Asia would be the development of missile defence.
Although still in it's infancy, in a few years or decades, development of a partial territorial missile defence to protect high value targets is a given reality. Only India seems to be developing a missile defence in south Asia with tangible results currently, which would give it a definite edge in power equations between the other two players, when implemented successfully.
I expect Pakistan to buy any such equipment when available from China, based on their past missile purchases (no offence meant to Pakistan btw), which leaves China to develop missile defence in competition with India. Apparently China is not doing so, so is it waiting for India to develop ICBMs first, or it simply doesn't have the technological expertise to do so?
I suspect the answer to this question will determine power equations in south Asia in the second quarter of the century.