I've got a sarcastic one, lol
DS definitely gets sarcasm and irony - has a great sense of humour in fact. I don't know that it's inherent in him though because it was definitely later than my DD understood things like that, I think it comes from living in our house
(is fairly sarcastic).
Idioms, well he doesn't get them but he's now past the stage where he takes them literally, he recognizes that they don't make sense or aren't relevant and asks what is meant.
He also has huge amounts of empathy - one you tell him you're upset, rofl, no he doesn't notice your mood at all, he tries, but he misses most things.
My friend's DD though has always tried to comfort people who are upset, from a very early age, much more than any other child I've ever known. She still doesn't like other people to be upset - she was very worried about me when I had to have my dog put down for instance, kept asking her mum to find out of I was ok.
I think it's very hard to say, it can't be Asperger's because they do... as everyone is different - Asperger's or not. It doesn't affect exactly the same things in different people.