This means that if you are using IBM messenger inside the Office firewall, you can still chat and exchange files with outside friends and family who are on GTalk, Yahoo or AIM messengers. They neither have to upgrade to Lotus Sametime and nor you have to install another IM client on the Office PC.
Now this could be an interesting deal to watch from the Microsoft perspective for two reasons:
One, Microsoft has always been shy in supporting the XMPP prototocol in MSN Messenger (Windows Live) that could make their software connect with rival offerings from AOL or Google. [Yahoo, an exception here]
Second, Microsoft is the second largest player in the enterprise messaging market (next to IBM) and it will be interesting to see how organizations react to the above news.
Not all of them would be happy to learn that employees can use the messaging system inside the office to pass on confediential data to someone outside the boundary using GTalk or Yahoo.
That could possibly make a winning case for corporates to make the switch from IBM Sametime to Microsoft enterprise IM (aka Microsoft Office Live Communications Server) for "security reasons".