Skype has just announced that Skype 5.0 for Mac is now out of beta, and the latest version has added a range of new features to Skype for Mac including group video calls which is available as part of the Skype premium package.
If you want to use the group video calling feature you can test it out for free for 7 days, and then it will either cost you $4.99 for a day pass or $8.99 for a monthly pass.
You can find out full details of what is new in the final version of Skype 5 for Mac over at the Skype Blog.