Researchers at the university of Austin, Texas, have managed to create the first transistor using silicene, the equivalent of graphene but based on silicon atoms.
Silicene till last decade was just a theoretical material. Now it is available and researchers have started to play with it and at Austin they have managed to create the first transistor. Potentially, silicene would allow the construction of much denser chip and most importantly chip that use less power.
However, this is just a demonstration of feasibility in a lab. What would be needed is an industrial process to manufacture silicene based chips. The researchers point out that the semiconductor industry has plenty of experience in manipulating silicon, something that is missing in carbon. Hence they claim that it should be easier to create an industrial process for creating silicene based chip than graphene based chips.
I personally do not expect to see silicene, nor graphene, take over the present silicon industry. What I consider likely is that in a few niches we will see custom chips based on new materials to meet very specific demands (like ultra low energy requirement). These will slowly grow in market penetration and eventually may displace current silicon chips (and current manufacturing processes). It will be a long transition though. Scientists are still working on perfecting and tuning the silicon industry (like moving to massive 3D architectures and lower power requirements) and this will delay any take over.