Some time ago I reviewed John Horgan's book The End of Science. Horgan suggests there that we are approaching the end of the period in which fundamental discoveries in science will be made.
If you find this idea depressing, as I do, have a look at What remains to be discovered?
on the BBC home page. Here the President of the Royal Society, Bob May, presents four first-rate programmes in which he talks to leading researchers in their fields. The subjects tackled are cosmology, the brain, physics, and the nature life. Excellent stuff.