Des O'Sullivan: Why are we still waiting for a burst of creativity in 21st-century art?

Burning gas station by Ed Ruscha at Christie's 20th Century evening sale.
The burst of creativity in the art world in the first two decades of the 20th century has not been matched in the 21st, and it is interesting to speculate about why. A century ago the world was newly enriched by Post-Impressionism, Cubism, Abstraction, Suprematism and the rest.
In the global village of today, development of the shock of the new in art does not seem to have occurred at the hectic pace of technology and other groundbreaking disciplines. Are artists stupefied by the pace of change in the world all around them? In a world where wonder is taken for granted is visual surprise and delight degraded?