Steve Rubel has a blog post entitled Dissecting Windows Live PR with Data where he uses the infamous Alexa traffic chart which has become popular among bloggers and other amateur pundits to dissect the populariity of a website. Specifically he writes

According to Alexaholic there was a lag between these news events and when the site became a regular visit for many consumers. In other words, it took Windows Live a considerable amount of time following the launch to build any kind of critical mass. (A caveat here. Alexa data is questionable when measuring true traffic data because it amounts for a small subset of the total browsing public.  However, the overall trends it shows I feel are bankable.)

I've noticed that quite a few folks have misinterpreted the traffic spike within the past month for the live.com domain in Alexa. If you take a deeper look at the Traffic Details for Live.com you'll notice the following data

• login.live.com - 46%
• mail.live.com - 38%
• ideas.live.com - 6%
• live.com - 4%
• local.live.com - 2%
• help.live.com - 1%
• expo.live.com - 1%
• safety.live.com - 1%
• Other websites - 1% 

That's right, the largest chunk of the traffic for the live.com domain is split between the Passport Windows Live ID login page which is now being used by most MSN and Windows Live services when signing in. The second largest slice is for the Windows Live Mail beta. I don't think one can draw any conclusions on the 'adoption' or popularity of Windows Live based on this data.