This assumes WebAssembly will have virtually no performance overhead when compared to C/C++, and still doesn't address the fact that JavaScript "binaries" will be much larger than today's scripts that rely on a JavaScript interpreter being present inside the browser.
> This assumes WebAssembly will have virtually no performance overhead when compared to C/C++,
It won't have zero performance overhead, since unfortunately it will still require translation to native code. But it'll be far higher-performance than asm.js, and precompiling JavaScript to WebAssembly could produce higher performance than a JavaScript JIT.
> and still doesn't address the fact that JavaScript "binaries" will be much larger than today's scripts that rely on a JavaScript interpreter being present inside the browser.
You don't need to do the compilation in the browser; do the compilation ahead of time and ship wasm bytecode. The DOM and all other web APIs will still be provided by the browser, so I don't see any obvious reason why wasm needs to have substantial size overhead compared to JavaScript.
