Never caught it's meaning as a "hug emoji"... Been using it to refer to a gesture that a dear friend of mine does with her hands though. Guess the meaning is in the eye of the beholder(s)?
I never thought of it as a 'hug' either, somehow I always saw it as a person with really tiny hands :-o
That doesn't look like a hug at all.
Also I liked how with the MSN one you could say ({) and your friend would reply (}). There is something meta about closing a brace there too... Ohhh, nostalgia.