I don't know what to add, except my condolences.
As other people have said, it seems odd to be so affected by the passing of somebody I've never met, but good writers—and David/TEV was certainly one—put much of what's best about them into their writing. I never met David, but I feel like I knew an important part of him, and I valued his contributions here and in Soccer in a Football World very much.
The Exploding Vole's voice was one of the many that made me realize what a special "place" OTF is when I first discovered it a few years ago. That he was an American football fan who appreciated the international aspects of the game without snobbishly dismissing the U.S. game made me feel I had found a kindred spirit, and one to emulate. Like Sam, above, it wasn't till I had been posting here awhile that I found out that not only did he not dismiss U.S. soccer, he had written an excellent history of it, which I had read when it first became available at the library, years before I found OTF.
The fact that soccer has been so marginal until recently in the U.S. gives Soccer in a Football World an interesting feel, much like other great histories of hitherto neglected or underground subjects, like The Making of the English Working Class, or A People's History of the United States, or even Our Band Could Be Your Life. Like all the better books about sports, it's about much more than sports and athletes, but gives a window onto the larger world. I am very sad that TEV won't be able to share his knowledge and insights on this board anymore, but incredibly grateful that he left us so much to read and reread and learn from.
His last words to us, above, are dreadfully sad, but also inspiring. I send my best wishes and condolences to all his family and friends, and to everybody else who appreciated his books and his posts on OTF. He is truly missed and mourned by people all around the world.