I've never heard anyone use the word "skyping."
Very common for me.
Also common are VOIP conference lines where everybody dials in.
When someone says "let's Skype" in my world, they either mean Skype-to-Skype (which is implicit if they are in your Skype contacts) or Skype-to-VOIP using one of our VoSky appliances that's tied into our PBXes. The verb "to call" is almost meaningless these days.
My wife does. Oprah's been skyping in and out of viewer homes for months.