Announced in April, the new version of iGoogle that brings social applications is tested in a small number of randomly selected Google accounts.
The new iGoogle places the tabs on the left-hand side of the page and you can expand the tabs to see the list of gadgets and status information, like the number of unread Gmail messages. There's a new chat feature borrowed from Gmail that lets you chat with your contacts while visiting iGoogle - that means iGoogle gets a sense of presence because you'll know when your contacts are online. Since the chat feature will be enabled by default, it's obvious that Google will be able to add options for sharing items and discussing posts with the contacts that are online.
iGoogle also adds a list of updates from your contacts similar to Facebook's newsfeed: you can see stories shared by your contacts in Google Reader, recent photos uploaded to Picasa Web Albums, Google Talk status messages, shared iGoogle themes and gadgets.
Another change is that gadgets have an expanded interface, called canvas view. Gadgets authors will take advantage of this to display more information and make their gadgets more interactive, while your feeds can be read in a Google Reader-like interface. In the future, iGoogle will support OpenSocial applications and the transformation to a social site will be complete.
Google announced that the canvas view will be rolled out to a small percentage of users this month and to more users in July, while the OpenSocial applications "will not work in production until later this summer".
Update (Oct. 16): The new iGoogle has been launched.