There was no reason given for discontinuing Facebook chat integration.
"We understand that this may disappoint some of our customers, but we hope that you'll try Skype for Outlook.com chat, and voice, video calling, so you can take advantage of the more robust ways to keep in touch with friends and family," the e-mail message from the Outlook.com team said.
I've asked Microsoft if the company has any more to say about the reason for the discontinuation of Facebook Chat or Google Chat support -- beyond the desire to push the company's own Skype instant-messaging service.
A spokesperson sent the following statement:
"Most Outlook.com customers already prefer to use Skype when they are chatting and we see this as a great option for anyone impacted by Google's decision to shut down Google Talk and associated APIs, or the recent deprecation of Facebook Chat for Outlook.com."