I'm slightly surprised to find that nobody has posted about this as of yet!
Personally, I am awed that the European Space Agency has been able to drop a lander on this comet. For those of you who have an idea behind the math and engineering required for this, you're likely as impressed by what it takes to get this spacecraft off of Earth and out to match the velocity and orbit of this comet without burning huge masses of fuel.
For those of you who are less technically minded, you have to realize it takes huge amounts of energy to get a mass out of Earth's gravity. The total mass of the Rosetta spacecraft and Philae lander together with the fuel for them is 3000kg. To get this free of our gravity took a 777,000kg rocket!
Now, the spacecraft does one orbit around the sun before using Earth's gravity to give it a speed boost. It continues on and uses Mars' gravity for another boost, then twice more getting boosts from Earth before going into deep space to meet up with the comet. Just the timing to match all of the orbits with the gravity boosts (two planets, one comet, four passes past planets, matching the comet velocity, etc.) makes you wonder what the launch window looked like and how long it would be if it were missed.
I'm looking forward to seeing what information they pull from this project!