I have skype on my focus and my lumia 900. My lumia was updated weeks ago when the last update came out. I just updated my focus and the version number is 220.127.116.11. On my lumia the version number is 18.104.22.168...and there are no further updates it. Don't know why the difference though...what phone do you have?
I've ATT unlocked HTC Mondrian (7Surround). I'm using in Saudi Arabia. Today, I received the Skype update 22.214.171.124. Can't find what's new in the update (or changelog). They shouldve updated the description! As others are suggesting, I believe it's about minor bug fixes on marketplace.
PS, IMO Skype team must post blogs about all the major/minor updates at blogs.skype.com.. in contrast with blogs.msdn.com/ie; the way IE team addresses the community!