Analysts have dubbed graphene a “wonder material” for its intriguing properties: stronger than steel, harder than diamond, thinner than paper, more conductive than copper, transparent, and flexible. Last year, 10,000 research papers were published about the material and there are thousands of patents, with Samsung owning the majority. IBM [IBM] and Xerox [XRX] have smaller patent portfolios as well. It is estimated that over $1 billion is invested globally in graphene each year.  Meanwhile, the market size is a mere $9-15 million due to limited commercial applications.  
Graphene is most notably used in tennis rackets, although the amount actually involved is kept secret. Also, the added properties graphene gives rackets are questionable, so this potential market appears to merely be a marketing gimmick. 
In most cases, the super material is limited by the difficult and expensive manufacturing processes required to harvest it. Graphene is cumbersome to manipulate and difficult to produce in large quantities of high quality. Researchers also question the health and environmental effects of both graphene and its manufacturing processes. Still, companies like CVD Equipment Corporation [CVV] continue to invest, and it seems everyday a new group of researchers discovers a new production method or additional applications for the material. Analysts forecast the future market size to be anywhere from $400 million to over $1 billion in the next decade.  
Is it all just hype? A few decades ago buckyballs  were all the rage with researchers, only to find no major commercial applications. Graphene could be on the same doomed path, but it is too early to dismiss the material. Silicon was discovered in 1824, but was not used in commercial transistors until the 1950s.  Graphene may still be decades away from proving itself as a viable commercial product.