Kittens are the coolest things ever, and so cute. Make the most of the kitten era, they just grow up so fast :D .
Jonathan Morris would say that we find kittens cute because they have a lot of features (big eyes, fur, etc) in common with what our babies would have looked like when we were monkeys. We are programed to instictively go soppy and want to protect them , it's an instict that ensured our species was sucessful.