First, it's really amazing that we have detected so many already. The number is growing really fast now, but soon the figure will really start exploding. Even better, we're now getting good at detecting tiny planets like our Pale Blue Dot.
But what is really mind-blowing is that these are just an infinitesimal fraction of all the planets that are out there. Think about it: our galaxy alone contains a minimum of 100 billion planets. Of those, most are small planets like ours: 10 billion terrestrial planets.
Statistically, every star would have at least one planet, according to the most recent studies. And there are about 500 billion galaxies in the universe. It really boggles the mind. [XKCD]