"Office Live Add-In"

Windows Update is offering me something called "Office Live Add-In."

Is this something I want?

If so, why?

Haven't been able to find much specific from MS about what it actually DOES. I am somewhat leery because it took me ages last year to get rid of some darn small-business something-or-other that was a Genuine Microsoft Product but gummed up Outlook something terrible. Now that I have Office playing nicely, I hate to add a new feature that will act like a bug.

 

That link was about all I could find. If I wanted to go that that mode of document sharing, I wouldn't use the Office Live site because (1) I'd worry about confidentiality/security; (2) the capacity wouldn't be big enough, at least for my business. Thanks for the input.