The Null Device
After some 15 years of development, the first program has run on the GNU Hurd, the earth-shatteringly nifty microkernel that will form the heart of the free-software-based GNU operating system and lead it into a shining future. Which means that we can soon expect to see GNU casting off the imperfect compromise that is the "Linux" kernel and assuming its rightful mantle of glory. Either that or a few wild-eyed, bearded GNU zealots and OS theoreticians vocally adopting the Hurd while the rest of the world says "yeah, whatever" and keeps using Linux (which, after all, is good enough and well-supported).
Or maybe none of the above; perhaps the Amiga will come back and dominate the OS world instead or something; who knows?