I've been programming JavaScript professionally for ten years and have interacted with thousands of JavaScript developers online and offline. I have never once heard anyone call the language ECMAScript except when they were specifically referring to the ECMA-262 specification.
Edit: After writing that I thought back, and now I do remember one time when somebody called the language ECMAScript when they weren't referring to the ECMA standard. I think this was the exception that proves the rule!
Edit: After writing that I thought back, and now I do remember one time when somebody called the language ECMAScript when they weren't referring to the ECMA standard. I think this was the exception that proves the rule!