I assume that you mean changes in interpretation rather than the formal changes in the amendments. Either way, yes, the Constitution is still relevant, and remains the point of reference for our courts as well as the basic framework for our government. The recent Supreme Court case on the Affordable Healthcare Act is an example. It hinged on a particular interpretation of the Commerce as well as the Taxation clause in the Constitution. Another example would be the Electoral College, which, while straying far from its original intent in that electors are essentially "rubber stamp" voters, will still decide our election no matter who wins the popular vote. You can say that we interpret the Constitution quite differently today, but not really that it is no longer relevant.