Personally, I'm not much for using Messenger, although I do regularly connect to an IRC channel. However, I know there are many people who do use WLM regularly. That won't be the case much longer unless you are in China.
There isn't much information out yet beyond Microsoft confirms Windows Live Messenger retirement in favor of Skype (http://www.theverge.com/2012/11/6/3609924/microsoft-messenger-retirement-skype).
Information and download: Skype (http://beta.skype.com/en/)
Skype blog post announcement: Skype - The Big Blog - Talk to your Messenger Contacts on Skype (http://blogs.skype.com/en/2012/11/skypewlm.html)