"Socket-layers are critically needed for such services as VOIP aka Skype, Viber, etc. We now know that multitasking is coming to Windows Phone 7 with 'Mango' but now we have a very strong hint that socket-support, in some way, may be coming as well."
Services such as Skype have long lamented the limitations in their ability to develop their applications for Windows Phone 7. Apparently Microsoft has heard their cries and are considering adding this functionality in an upcoming update. It's one of their "top 2 or 3 requests from developers". Official announcements have not been made, but Brandon Watson definitely hints here at a possible official announcement at MIX11. In any case, we can look forward to more exciting announcements at MIX11.