Some sort of problem -- which many believe had to do with Microsoft's Live services -- blocked certain notification and app-update capabilities on Windows Phones in the U.S. for the past several days. Users are reporting as of the morning of January 16 that the issue seems to have been resolved.
I myself noticed on the evening of Friday January 13 that the notifications on my "Me" tile were no longer working. That meant I couldn't see mentions from Twitter or Windows Live there. I could, however, see them if I used the Windows Phone Twitter client. Quite a number of other users were experiencing the same issue, with some saying it hit them starting Thursday January 12.
Microsoft officials didn't have much to say about what was going on. I asked for more information on January 14. On January 15, I received word from a spokesperson that "we are investigating these reports and will provide an update when we have more to share."
Then late on January 15, Windows Phone users began reporting that the problem was fixed and the notifications were working again. I asked Microsoft for another comment as to what took down the notifications service and so far have received no reply.
One of my contacts on Twitter also said that he was unable to update any of his Windows Phone apps over the past weekend. He said he received an error message that said Live Services were unavailable. He said the issue resolved itself at the same time as the Twitter problem was fixed.
In other Windows Phone news, Microsoft execs said at last week's Consumer Electronics Show that Windows Phone users will get a Skype app "soon." Microsoft officials said last year that Microsoft planned to deliver Skype for Windows Phone around the same time they rolled out the "Mango" operating system release (which was fall 2011).
When no Windows Phone Skype app materialized, rumors began circulating that Microsoft's phone team had decided to scrap the promised app and instead were planning to integrate Skype directly into the phone platform. But based on last week's information, it sounds like the plan is to deliver a Skype app for Windows Phone first, followed by deeper Skype integration into the operating system later this year, possibly around the time Microsoft is expected to roll out the "Apollo" Windows Phone operating system.
Update (12:30 p.m. ET on January 16): Still no word from Microsoft as to what's happening. But after a few hours of functioning properly, the Twitter notifications on the Me tile broke again for me and a number of other Windows Phone users. As one of my Twitter contacts @jubbing suggested, I restarted my phone (not a hard reset; just turning it off and on), and that seemed to fix the problem. Also: This doesn't seem to be a U.S.-specific problem. I'm hearing from some users in other countries they're also affected.
Update 2 (1:45 p.m. ET on January 16): And here's the official Microsoft statement on what happened and when it will be fixed, via a Microsoft spokesperson: "Late last week we began deploying a server update that inadvertently turned off our Me Tile Twitter feed. We’re on it and expect to have everything fixed shortly."