Are all fossil fuels from fossils?

The current dustup over the Keystone pipeline has conjured up one of my nagging questions. Call me crazy but I have always been skeptical of those who assert that we will run out of fossil fuels. This has always been a basis for advocating "alternative" or "renewable" energy as well as all the hand wringing on CO2 emissions. I guess the animals are not dying quick enough and decomposing rapidly enough to keep up with demand and even if they were we would die of pollution and global warming first. However, a couple of years ago I recall reading an article in Scientific America that indicated that my speculation was not entirely fanciful (http://www.scientificamerican.com/article.cfm?id=fossil-fuels-without-the-fossils). It is about a process know as abiogenic hydrocarbon genesis. Here ethane and heavy hydrocarbons are produced under pressure below the earth's crust. This may not be entirely fanciful since some scientists have argued that the new oil and gas discoveries well below the surface of the earth could not have originated from fossils due to the depth of the reservoirs. If this is true then the world will not run out of oil and gas regardless of the rate of demise in animals and plants. Such a discovery would speed up all the deep drill technologies and decrease the importation of oil world wide as more and more finds would occur throughout the world.