As you mentioned, there's the socializing aspect. For me, it's 'getting away' for awhile, even if it's just for a weekend. I don't have any other distractions and can focus on my projects. There will often be quilt shops that are new to me and that's always fun too. Those are the first things that come to my mind.
I really enjoy quilt retreats. They're rejuvenating, relaxing just plain fun!