Currently it was launched for a limited amount of users in a per-invite basis. (Good thing I was able to find a nice blogger who was able to invite me in the said networking site. All thanks to Daniel Mortiz of chopsueyrice.) I'm not specifically sure of this, but I think Google+ is still on it's open beta stage, probably for bug testing.
Google+ integrates and connects other social services such as Google Buzz and other google services and products such as Google Profile, Picasa and GMail. The term circle was used by Google+ to refer to organize your contacts that can even be categorized to groups. It has also a place called hangouts wherein (never tested yet due to small my number of contacts on the said networking site; this description is based on wikipedia) you can facilitate a group video chat (with a maximum of 10 people participating in a single Hangout at any point of time).
Due to this new service, most of Google's services and products has undergo UI (User Interface) updates including Google search, GMail and other services under the said company. On the other side of this, there are also cases I have heard that some services are having access issues and other request related errors. Also I notice that once you logged in to google groups, you'll see a highlited text saying the following:
As of [A_CERTAIN_DATE_THAT_SEEMS_TO_BE_CHANGING?], Groups profiles have been disabled. Your profile information will be available for export from your profile until [A_CERTAIN_DATE_THAT_SEEMS_TO_BE_CHANGING?]. This change will not affect the nicknames you might have chosen for yourself to participate in groups. It will only affect the custom profiles fields, such as your photo, location, and occupation. More details are available here.
This text seems to be tied up with google profile that seems to be affected of the launch of Google+. With this issues regarding the services, could it be the same reason why some sites are reported to have sudden drop of visitors and ranking? I'm still trying to resolve this by finding if it has any connection to the said launching.
Right now, i'm still trying Google+, who knows it'll grow as it was planned.. Google seems to be trying to conquer the networking sites (right after creating their own browser and operating system), probably in the next few years they will be launching their own country or planet.. :)
UPDATE: For those who want to add me see gplus.to/ajibanda and for those who want invites, you can simply email me via Contact page. Thanks
*Image from www.xkcd.com