There are two views to each web part page, the shared or public view, and the personal view.
If you go to the Welcome menu and select "Personalize this page" you will see this message:
Version: You are editing the Personal Version of this page
If you go back to the Welcome menu and select "Show Shared View" and then edit the page (Site Actions, Edit page" you will see:
Version: You are editing the Shared Version of this page
Microsoft is conducting an online survey to understand your opinion of the Msdn Web site. If you choose to participate, the online survey will be presented to you when you leave the Msdn Web site.
Would you like to participate?