A beta version of Skype 5.0 for Mac has been released, and it includes not only some new features like group video chat, but also becomes more Mac-like by putting all of the information and controls in one window. The existing Skype client scatters windows hither and yon; one for chat, one for a list of contacts, and so on.
The Mac Address Book is now integrated with Skype, so you no longer have to keep a separate contact list for the app. Adding new contacts is much simpler than before, requiring just a search and single click to include them in your list of Skype users. To dial people directly or send SMS messages, there's now a floating dial pad that appears when needed. A new sidebar in the all-in-one window features your contacts and contact groups, as well as providing access to recent conversations.
But the biggest feature so far is group video chat. All participants in a Skype group video chat need to have Skype 5.0 or greater for Mac or Windows running on their machine. It appears that you can chat with up to three other people. There's also a "push to talk" feature that can be enabled to require you to push a certain key combination (Control-Option-Command-Up Arrow) to speak. When you remove your fingers, you're automatically muted. Frankly, I think they could have used something a bit more simple than that key combo.
A video discussing these features is on the next page.