A US state will secede (30%).
I don't see that happening -- which one or ones do you think are most likely to leave?
Scotland may well leave the UK (10%), or the UK leave the EU (15%).
Texas is probably the most likely but I can imagine a number of other possibilities. MatthewB's post above outlines a plausible case for California for example.
I would like to propose this as a thread for people to write in their predictions for the next year and the next decade, when practical with probabilities attached. I'll probably make some in the comments.