I know what you are thinking already: the c-word came to your mind - the one many snobbish physicists use to describe laypersons with a theory of everything in their pocket. George is not in that category, however. First of all, he is a real physicist with a PhD (Yale University, 1993) and post-doctoral studies (Univ. of Toronto, Alex von Humbold fellow at T.U.Munich, and at the Technical University of Athens until 2002). The fact that he later left academia to follow a career as a derivatives-market maker only shows he's smarter than the average physicist... And second, his approach to the unsolved mysteries of physics is a more aesthetic one than a brute-force "I have the solution" kind of thing.
In his book, George does introduce some ideas of what could lay beyond, and gives even a name to new particles that increase the symmetry of the world of subatomic particles: he calls them "katoptrons" to encapsulate in their name his concept of a mirror world. If you took his book as an attempt at a theory of everything, however, you would be wrong. It is rather a book for laypersons, where George's penchant for outreach is evident. Most of the book in fact explains known physics in simple terms, and with some clear emphasis on the appreciation of the aesthetical traits of the construction.
The connotation of the work and its aim at laypersons is clear also from the presence of a very rich glossary at the end, where things like "background radiation", "coupling parameter", "order of magnitude", "Planck energy" get explained in easy terms. But what surprised me the most is that the text in the book is neatly complemented by pencil drawings that show he is also an artist, with definite surrealistic influences. I must say I liked many of his drawings, and I am reproducing one of them below.
The book is available here at a reasonable price.