Windows Live Mail version M7 is almost ready. Some changes to this release are:

1) Checkboxes (the best!!):
You can select messages the same way you used to in Hotmail. It was pain holding the Ctrl key while selecting individual messages

2) Better Signing in to Windows Live Mail:
The Set-up wizard for first time users using Windows Live Mail is now easier to use
- New loading page with a link to try the basic version if your connection is too slow.
- The Today page will now have your storage meter, updated contacts, and updated Spaces for quicker access too.

3) Contact Importer
-A new contact importer will let you import contacts from Outlook and Outlook Express
-Share your contact information with friends on the “You” contact on contacts page.

You can also try this release by doing the following:

1. Login to Windows Live Mail
2. Navigate to http://by101w.bay101.mail.live.com/

You should now be able to see Windows Live M7

Via LiveSide- this and this