One question that has come up again and again in the history of science is, when and will we be done? Do we eventually reach the end of the ability of humans to understand our world? or is the universe simple enough to understand. So far it has paid to be an optimist, but I do often hear things that make me think the end is near. This century was supposed to be the century where biology rises in knowledge and importance, yet it actually seems to be getting less productive. The last decade has been one of decreasing returns in the biomedical industry:

"Only 17 new molecular entities were approved by the U.S. Food and Drug Administration (FDA) in 2007, a fall from 53 in 1996." Source

Moore's law is also coming up on an end, although predicting the end date is a game of fools. We do know transistors will remain bigger than atoms, that is a sharp limit on what we can do. Now, we clearly have enough science to go around for my lifetime, but it will be interesting if when I am retired science will manage to continue to find new discoveries at anything like the rate it is.