Imran Qureshi, Windows Live Program Manager, blogs the story:
The wait will soon be over. This week we will be releasing the “M4” (Milestone 4) update to the Windows Live Mail beta (codename: Kahuna).
We listened to what you, our beta users, told us. We fixed many of your issues, improved reliability, made Kahuna even faster and added some great features that will improve your mail experience.
Hit the link for a list of new features and some screen shots. I liked the “spell check as you type” which seems novel for Web app and it’s great that M4 supports additional browsers including Firefox, Netscape, and Opera. Unfortunately, it’s still a closed beta, but if you want to get on the waiting list, you can sign up here.