No not necessarily- I never use the phrase so long with anyone but it would not be a very strange thing to hear- if i was parting with my friend i would say something more like "bye" "see ya" "see you later"

I don't know if it is a regional thing, as other posters seem to not use it, but in northern England we use it quite a bit.

It's more common amongst those who are close, as in an endearing farewell when you are going to miss someone.