Though I haven't programmed in it beyond toy problems, Rust is exciting because it actually has an answer to the question of "why would you use this instead of C/C++ for systems programming?" and the answer is memory safety, concurrency, and rich, no-cost abstractions. It also has a good story for interop with C.

Having an answer to that question is necessary, but not sufficient. There's also a lot to be said for being in the right place and the right time---who'd have thought in the early 2000s that Objective-C would suddenly become a hot language? Killer apps like the iPhone can make a huge difference.

It's still early days. Industry standard languages have lifespans on the order of decades; C is rougly 45 years old, C++ roughly 35 years old. I think Rust has a chance, but we won't really know until it's a decade old.