Today it seems like Microsoft have flipped the switch and turned on the menu for Windows Live Groups in the new Messenger wave 3 beta! When you right-click on a Groups’ name the following option menu will pop-up:
Previously these options were greyed-out, but today they’re being activated and directs you to the appropriate websites associated with the Group (we’ll talk about Groups more in-depth later). Unfortunately most of these links currently directs you to the 404 “We can’t find that page” page you’d get when you visit any of the beta urls we’ve found previously…with the exception of one – Groups Calendar! 
Clicking on Calendar in that menu will direct you to your Groups’ Calendar, as shown below. You can even set the theme for your Group here:
Although it doesn’t seem like it’s connecting yet (notice the “Group name goes here” text on the top), at least it gives us an idea of what’s to come! Oh and did we mention the URL it directs you to also gave away the address of the new dogfood Calendar server? Take a look - it works for your own personal Calendar too! Although it seems to be only 11 days newer than the public release, and the only difference I can see are the “correct” links in the wave 3 header, but hey - you’ll never know when they will give us the next surprise! 