Since concepts got “yanked” from C++0x (see my post on the subject) I’ve been keeping a closer watch on comp.std.c++ than I usually do.
Aside from generic meta-programming a,d threading, one feature I really like about C++ is its ability to do functional programming. Lambda expressions are, of course, a favorite when doing functional programming - though currently C++ doesn’t allow them very elegantly. In this post, Mathias Gaunard proposes polymorphic lambdas be put back in C++0x. How much fun could we have with that?!