Microsoft is expected to make available to testers this week the first beta version of its Windows Live Messenger instant-messaging service.

According to a posting on the MSN Messenger enthusiast site Mess.be, Microsoft will launch the first Windows Live Messenger beta test on Tuesday, December 13.

Testers report that they have received beta invitations from Microsoft for the new beta over the past couple of days.

The new Windows Live Messenger will be "as fun and reliable as the Messenger you already know, and you lets you keep the contact list and other personal stuff you've got stored in Messenger," according to according to a copy of the beta invitation posted on the ActiveWin.com site.

Microsoft will be including additional VOIP capabilities in the first Windows Live Messenger release. Microsoft first added VOIP support to MSN Messenger as of the MSN Messenger 7.0 release.

According to sources, Microsoft will offer Windows Live Messenger users the capability to place calls from PCs to any phone. Microsoft will deliver that capability in conjunction with MCI, sources said, whereby MCI will sell Live Messenger users blocks of VOIP time.

Microsoft officials declined to comment on the pending Windows Live Messenger beta release.

The new Live Messenger release "has a fresh new look and feel, and lets you do things you've never done with Messenger before, like: Make domestic and international PC-to-telephone calls at incredibly low rates (you'll need to sign up with a Microsoft Partner, but you can do this in seconds, right in the Messenger interface.)," the invitation continues. "Drop documents into special folders that you and your contact can access even when one of you is off-line."

Mess.be is identifying the forthcoming release as 8.0. Earlier this month, Microsoft made available for download the final version of MSN Messenger 7.5.

To date, Microsoft officials have been reticent to say publicly that Windows Live Messenger is simply the new name for the next version of MSN Messenger. But that is, in fact, what it is, sources close to the company confirmed.

Microsoft officials also will not discuss whether it plans to whittle down the number of instant messaging (IM) clients it supports. Microsoft currently offers three different but somewhat overlapping IM clients: Windows Messenger, MSN Messenger and Office Communicator. Officials declined to say which of these Windows Live Messenger will supplant.

When it rolled out its Windows Live strategy in early November, Microsoft identified Windows Live Messenger as a service that will help "individuals deepen their connections with the people they care about through instant messaging, file and photo sharing, PC-based calling, and more."