Windows Live was born on November 1st, 2005; and now, almost seven years later, with Windows 8 and Windows Phone striding towards more meaningful cloud services integration than ever before, it is about to undergo some serious changes. Want to know more about it? Check out the following post - "Cloud services for Windows 8 and Windows Phone: Windows Live, re-imagined"
Another update (11/19/2013): further evolution of Office 365 services makes creation of distribution and security groups even easier, plus there's now an option of creating a dynamic distribution group (click here for more information): Update (08/06/2012): a clear sign of Office 365 evolving along the same lines as other agile cloud services - small incremental features and minor new functionality are being delivered almost continuously and, unlike important major service updates, without much fanfare. For example, there's no need to resort to using PowerShell to setup mail-enabled security groups anymore, it can now be done at creation using management portal: Those managing Office 365 ( O365 ) tenant via the Microsoft Online Services Portal ( MOS Portal ) interface would notice that there are two distinct group entities: Security Groups: can be created via MOS Portal (main portal page>Management>Security Groups) and used for assigning