Skype is actively testing a new video messaging service with a "group of mobile and mac users" according to its official Twitter account today. The new feature, which doesn't require a new update to the mobile app, enables users to send video messages back and forth up to 3 minutes in length. If you've been selected to be part of this initial test, the option will be found under a contact's name in the "More" category, which now holds options to do video messages and send files. You get a basic video interface where you can press the record button to start, and when you're done hit the record button again to save and send the message.
The menu item clearly says "20 free video messages remaining", so we're going to assume that sending video messages is going to be a premium feature costing Skype credits going forward.