The thing that makes it different than Rehnquist remaining in the position is simply an age thing, as long as Rehnquist was CJ there was that chance that he would soon decide to retire, now both his replacement and the new CJ will be making decisions for the next twenty years.
His replacement's role is not as pivotal as that of O'Connor (now Roberts) but the difference between Rehnquist and even another extreme conservative is tangible.
I stand corrected, you are as vapid as they say.