Many of you might’ve realised that an old Milestone 2 build of Windows Live Essentials Wave 4 has been leaked to the web (we heard that development is currently at Milestone 3). From the screenshots leaked, you might’ve noticed and wondered about a new icon in the installer – called Companion. In Milestone 3, this little piece of software has been renamed the Windows Live Messenger Companion, and will be available along with Messenger, Mail, Writer, Photo Gallery, Movie Maker, Family Safety, Sync, as well as new additions such as the Outlook Connector Pack and Microsoft Silverlight (KB960353) (thanks Ugosan for the tip!).

So, what exactly is Messenger Companion? This is what a description of it tells us:

Messenger Companion
Share a webpage with your friends on Windows Live right from Internet Explorer. See pages your friends have shared and add comments to shared pages.

To be exact, Messenger Companion is a browser add-on for Internet Explorer which allows users to share websites they find interesting with their Messenger contacts (except to be integrated with the new social feeds). Here’s a screenshot:

(the above screenshot is taken from the older M2 build, and do expect considerable changes to the UI in later versions)

Messenger Companion will also allow you to view what your friends have shared about same website you’re on, as well as any comments posted for these shared links.

Personally, it seems to me that Messenger Companion is replacing the original “Share” functionality of Windows Live Toolbar (Windows Live Toolbar will be discontinued in Wave 4, and replaced by Bing Bar), pretty much the same way Windows Live Sync Wave 4 will replace the original “Favorites sync” functionality in  Toolbar. However, it does seems like Messenger Companion will have the potential to become the future bridge between Windows Live and Internet Explorer.

Stay tuned at LiveSide as we bring you more Wave 4 news!