I have nothing worthwhile to add on this glorious occasion, but I wanted to make sure I collected a few notable updates and details for future reference.
A good summary of what Rosetta has had to do to just get in reach of the comet.
To see Rosetta's full journey and to get a sense of the planning that must have gone into making this happen, the ESA have an excellent animation capturing the entire mission lifecycle.
On the way there
On the comet
Things may not have gone smoothly with the landing procedure and the eventual resting position and orientation, but it still makes for some fascinating pictures.
An event of this nature would never be complete without's XKCD's take on the matter:
I also strongly urge you to ignore the comments sections when you come across this story in the mainstream media. It's polluted with imbeciles that cannot (or refuse to) fathom the enormity of this achievement and the lasting value such missions provide. There is also the matter of the look of complete and utter awe when you explain to a five year old about how a mission conveived when daddy was a child, the results of which are now about 500 million miles from Earth, which has somehow managed to rendezvous and land on a small comet, and will hitch a ride on it around the sun and beyond.
It must have been some spreadsheet to pull off calculations on this scale and of this complexity
(I have a handy little list on Twitter via which you can receive further updates as the mission progresses.)
Update 19 November 2014
Goodnight Philae: A nicely written official statement confirming that Philae has entered deep hibernation in an attempt to save critical systems. There is still some hope that it can recharge its batteries enough to wake up as it approaches the sun.
Finally, this is the official ESA gallery of pictures from Rosetta of this stunning, distant world.