For "classic account" users, sign-in is here:  http://preview.channel9.msdn.com/SignIn

 

(The "Classic Account users sign in here" link on the LiveID sign in page leads to the current site, not the new one)

 

BTW, the day you switch to Live ID-only for sign-in will be the day I stop visiting.  Live ID (and switching between IDs) isn't worth it.