Rust may be a different story (still too soon to tell) because it shares many of the fundamental philosophies of modern C++ without having a "bolted-on" feel. Still, it will be very hard to ever displace C++, because so much code is currently written in C++ and C++ has proven to be a very good language for code that needs to last decades.

I'm pretty sure that Rust devs are aware of that which is why they made Rust compatible with C/C++.

This is one of my big frustrations with Go. I see lots of ugly `interface` based patterns.

I wish more languages would adopt Haskell's typing system (at least partially). It is truly beautiful.

For a small example, a friend talked me into implementing a few Scala collection operations in C++11. Here's the result: https://gist.github.com/LnxPrgr3/6547131

Usage looks like this:

    const collection<vector<string>> names = {"Daniel", "Chris", "Joseph"};
    return names.reduce_left<string>([](const string &total, const string &value) {
        return total + ", " + value;
    }) == "Daniel, Chris, Joseph";
    // ...
    const collection<vector<string>> strs = {"1", "2", "3", "4", "5"};
    auto rv = strs.map<collection<vector<int>>>([](const string &x) {
        return atoi(x.c_str());
    });
    return rv.size() == 5 && rv[0] == 1 && rv[1] == 2 && rv[2] == 3 && rv[3] == 4 && rv[4] == 5;

    struct test {
        const char *name;
        function<bool ()> fn;
    };
    
    const vector<test> tests = {
        {"Foldleft", []{ /* .... */}},
        {"reduceLeft on empty throws", []{ /* ... */ }},
        // ...
    };
    
    for(auto &test: tests) {
        cout << test.name << ": " << flush << (test.fn() ? "PASS" : "FAIL") << endl;
    }
    

This isn't at all an exhaustive list, but these are the biggest things that come to mind when I think of what C++11 gains over C++03.

In benchmarks Go keeps performing somewhere between Java and C++, but it isn't at the baremetal performance of C / C++ yet. Don't know if it can get there with its abstractions. Rust is closer, but it concedes a lot of glyphic syntax (such as requiring :: for scope like in C++ rather than, say, one colon) but I don't see it hitting prime time until Mozilla is ready for Servo to enter Firefox. It needs a big project behind it to show its capable.