New features include enhanced built-in security, shared search within the Live Messenger window, and the ability to set up a Sharing Folder with a friend that allows you to drop in photos and other stuff. Friends can see your Shared Folder items even when one of you is offline. It also features mobile messaging that allows users to send messages to friends on their mobiles, even if the contact doesn't have a messenger account.

As I said, I've played with the beta. Microsoft Live Messenger uses Verizon for termination and as far as I can tell they are an "exclusive" partner. (Wasn't IDT/Net2Phone Microsoft's exclusive partner in the past on Netmeeting?) I would have liked to have seen Microsoft support any SIP-based termination service provider. I also wish Live Messenger was able connect to any SIP-based phone system so it can act as a desktop call control application. For these two reasons alone, Live Messenger fails my litmus test for the "perfect softphone & IM client" that I recently blogged.

Soon Microsoft Live Messenger will support calling the Yahoo! Messenger with Voice application. Certainly, this deal between two IM heavyweights doesn't bode well for the Skype client which doesn't interoperate with any other IM client. Part of the reason is that Skype uses a proprietary architecture instead of using the SIP standard. Are Skype's days numbered?

Windows Live Messenger is far from perfect, but nevertheless, I will go download the new Windows Live Messenger. It is my primary IM client, but Skype is still my primary VoIP client - for how long remains to be seen.

If you want it, go here to download