Ever since Microsoft acquired Skype and confirmed the end of Windows Live Messenger, a merger has been a tiny dot off on the horizon. Now Microsoft has pinned down when the two will become one: this April.
Starting on April 8th, Messenger clients will start receiving updates that will upgrade them into Skype clients, and while the whole process will take a little to roll out, the plan is for most existing Messenger users to be shunted over to Skype by the end of April. It seems that this will mostly apply to legacy users who haven't booted up the actual client in a while. Die-hards will have to make the move to Skype manually when WLM dies on March 15th, or suffer a few weeks without.
Slowly but surely the transition is rolling out. Get your quality time in with Windows Live Messenger while you still can. If you care. [Skype Blog]