Chasing #1 Test Spot but can India hold on to it?

The media in India is going crazy with the fact that if India can win the last of the test matches against Sri Lanka, they would occupy the number one test ranking for perhaps the first time since the official ranking system was launched. However, one question begs to be asked - unlike the Aussies who turned out to be absolute rulers as the number one ranked test team, can India actually hold-on to the spot for a substantial period of time?
Their middle-order might be one of the best in the world right now, but a few seasons from now on and some of the big names are bound to retire. Where are the worthy replacements? Where are young, tear-away fast bowlers who can win test matches on their own? Even Bhajji has no one who can be called his ally in terms of a dependable, back-up spinner. I honestly believe, we are reading too much into the ranking updates. Let us get real, the points will come and go but the real test is of the fact that whether a team can be heads-and-shoulders above its immediate competition.