I've seen a couple of the "let's bring social networks to the workplace" products and quite frankly none have impressed me so far. The real problem is not providing great technology but actually getting people in corporate environments to use it in a meaningful way. These projects usually end in the same manner...network is rolled out, used for a couple of weeks and fades into obscurity rarely used (and often leaving an extra attack vector). Or in other words...most lose the battle to good old email.

That being said...this is potentially scary news for companies that are in the HR 2.0 business for lack of a better word. Typically their solutions have alumni management, stay in contact etc. that they tout. Well if your company has FB work and they later add the option to integrate private FB accounts of ex employees or something that's interesting. I know they say for now those are separate but I wouldn't be shocked if that changes eventually.

Edit: If they want to segment this they should have given it an entirely different name imo. I'm sure there are marketing people at FB that are way more brilliant than me but this seems like a typical positioning mistake. You think you need to rely on your powerful main brand when you really want to create a new brand because you're attacking a different positioning slot in customer's heads. Don't have my Ries/Trout book at hand but it sounds familiar enough that I'll browse through it at home.