Let's say you have a company running a lot of C/C++, and you want to start planning migration to new technologies so you don't end up like COBOL companies 15 years ago.
For now, C/C++ runs more than fine and there is plenty dev on the market for it.
But you want to start thinking about it now, because given the huge running code base and the data sensitivity, you feel it can take 5-10 years to move to the next step without overloading the budget and the dev teams.
What would be your choice and why?
D and Go will probably just become as popular as Python and Ruby are today. They each fill a niche, and even though D was supposed to be a full-fledged replacement of C++, it probably will never acquire enough mass to push C++ away. Not to mention that they both aren't stable/mature enough, and it's unknown whether you'll have support for these languages in 10-20 years for the then-current hardware and operating systems. Considering that C/C++ is pretty much the compiled language and is used in the great majority of operating systems and native-code applications, it's very unlikely that it'll go away in the foreseeable future.
C and C++ are a pretty much unbeatable combo when it comes to native/unmanaged/"lowlevel" languages.
Not because they're the best languages, far from it, but because they're there, they do the job, and they're good enough. There's little doubt that D, for example, is better than C++ in most respects. But it fails in the most important one: Compatibility with all the existing C++ code. Without that requirement, most of that code would be written in a managed language today anyway. The only reason so many codebases use C++ today is because they used it last year, and it'd be too much of a pain to switch to something else. But if and when they switch, they typically don't switch to D. They switch to C# or Java or Python.
The problem for D and other "upcoming" languages competing for the same niches, is that while they're better, they're not groundbreaking enough to motivate people to actually switch to them.
So C and C++ are here to stay. C is unlikely to evolve much further. It is as it is, and one of the niches it has to fill is "simplicity, even for compiler writers". No other language is likely to beat it in that niche, even if they never revise the standard again.
C++ is evolving much more dramatically, with C++0x getting nearer, and they've already got a huge list of features they want to do afterwards. C++ isn't a dead end in any way.
Both languages are here to stay. Perhaps in 50 years other languages will have replaced them, but it won't happen this decade.