Why is this such a lost art? Bring together those friends that would never have met other wise. Make the people you love, love each other.
I recently had a small birthday wine n dine with my friends and anticipated awkwardness between my different groups of friends, but it was the complete opposite. God I love my friends and love making a space for them to mingle and laugh in eeeee. I think in a time where my friends and I are transitioning to adulthood and focusing on careers, this brings something to look forward to and a way to create a world outside of work and study.