The world becomes technologically stagnant because there's no drive to innovate and develop new technologies now that there's no wars; and hundreds of thousands of people go unemployed now that their field of business (war, weaponry, national security, etc) no longer exists. A peaceful status quo is acheieved: no more wars, but no more change, either. For the rest of humanity's history, this, our current social landscape, will be the norm, no matter its pros or cons. We will never go to Mars or discover interstelllar voyage. We will never develop new means of communication. We will never truly explore the potential of clean, alternative systems; making us terminally dependant on oil. Global warming will never stop, and we'll have to bid farewell to a few countries as the years go by. The Maldives, the Seychelles, and a huge chunk of the Netherlands, all gone. Animals go extinct with the climate change. Diseases like the AIDS, Cancer, and the Common Flu will never have a cure now that they're simply seen as "manageable". Religion will eventually lose value, but soon the notion of culture and folklore will do the same, and so will the idea of "nation" and "nationality". There will be no borders, but there will be no sense of belonging, either. We'll live as we currently are for a couple centuries before we lose our own identity -- the human texture across the world. We will be as flavorless as the air, and like it, and in time, we'll be gone with the wind, without ever leaving a trace of our existence for whoever finds us in the vast emptiness of space.
I wish for a puppy.