I was just thinking that I should have added something along those lines just after I pressed submit. The current computer architecture may change in the future - and in fact one reason why the "popular language" will change is that processors change in overall architecture. In the current languages, it's pretty hard to generically write code that works in multiple threads. If the trend of expanding computer calculation capacity by more cores continue, we may find that "best performance" is achieved by a different sort of software design, which in turn means that the language used for that purpose may have to change to describe better how we would want things to work in a super-parallel computing environment.
We also can expect the boundaries between processor and graphics processor will further blur. Currently, I don't think this leads to a new language being needed, but I expect that current languages may not provide the right support if this continues [graphics processors also tend to be "super-parallel"].
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Mats