pYro_65:
Well actually, its not as new or unrelated of a concept in C++ as you might think. Your simple example would easily translate to a lambda.
I will definitely need to look more into it. I have never really used lambdas in C++, but they do seem very useful (as you said, perfect for short callbacks, etc.). However, it seems like they have only been added in c++11? Do you know if all Arduino IDE versions support it?
As @Robin mentioned, I am currently focusing on making the language beginner-friendly, so it is probably best not to introduce lambdas at this point. If I ever do in the future - I will also need to make sure that the syntax is simple enough and does not conflict with other language constructs.