It makes reading java more like reading lisp, which is a different way of thinking entirely. Personally I think it's a mistake to put functional programming into an OO language - it makes code harder to maintain as there are too many ways to do the same thing. C++ has become virtually unusable as a result of all the different languages they've mashed into it, and I'd hate to see java go down the same road.
Geez, the C++ hate is unbelievable. I use it every day, and it's a great language. No way is it "virtually unusable". Some of the criticisms are justified, but the way people carry on about it is just absolutely beyond overblown.
