Microsoft is constantly tweaking their Windows Live pages and may have also tweaked the Windows Phone page to include some interaction with your Windows Live Account. There is a screenshot on Japan's Windows Phone site that looks like a cross between the current Windows Live device page (shown below) and the Windows Phone page.
The web page screenshot reveals a My Windows Phone interface that includes your Find My Phone commands, access to your pictures and videos, plus access to your Windows Phone apps and view your Marketplace Account. You still have access to your XBox Live account and Office docs but gone is the Contacts and Calendar Portal as well as the Zune launch.
We followed the instructions found on the Japanese Windows Phone site's FAQ Page but the new design isn't live yet and you still get the "old" design of the Windows Phone site.
It is unclear if this is a redesigned page for Windows Live or a redesigned Windows Phone site that adds the ability to sign in to your Windows Live Account. The header on the Japanese site does resemble the current header on the Windows Phone site here in the States.
There's definitely more questions than answers but could this be how Microsoft plans on implementing the Windows Phone Marketplace online?