To reignite the C++/ Java debate once again...
Simply because I think its funny, and interesting.
This is the perfect type of system to write in C++ (or D?)
High performance required per node, years in the making, tuned up to its eyeballs to run JSON (eh, did I read that or make it up)... I'm assuming you write your logic in C++ as well though. In any case, this is absolutely the right tool for the job, as the C++ bods will no doubt crow about.
For the 95% (just made that up, did you like it?) of other coding duties, it has been surpassed by other languages that have different compromises that are better suite for the domain they are in.
So, dare I say it, C++ is extremely good in its domain, but it really should stay there.
Let the bun fight commence!