New languages are carried on the backs of new platforms. eg: unix & c; web & javascript.<p>To predict the next big language, predict the next big platform. The upcoming platforms are: smart phones & tablets; cloud computing & many-core. The cloud, being connected services, is largely language-agnostic, and many-core might end up being implemented by borrowing whatever works in the cloud.
The needs of the above seem well-met by established languages, leaving little opportunity for new languages to emerge.<p>What about the next big platform after the above? It's probably more than 10 years off, but Moore's law says smaller devices will come. If disruptive, they'll be attractive to new audiences, with different needs - perhaps along the lines of cochlear neural implants (already big business) or garage genetic-engineering. What languages do those guys happen to be using? They will be carried to success.