Today, 22 October 2012, FamilySearch.org has been down most of the day and unavailable. However, it is likely that this downtime in in preparation for the "Official" introduction of the program during the week of 29 October to 2 November, 2012. The Mesa FamilySearch Library received an email announcement to that effect and has been sharing the information with all the Library volunteers.
I am not really certain what will happen to the program in conjunction with the Official Announcement, since it has been operational for some time and available to anyone who wanted to register and obtain the freely available invitation. What is likely is that Family Tree may now appear on the FamilySearch.org menu, with or without signing in. I doubt that the connection between New.FamilySearch.org and Family Tree will be severed until the users of both programs have gotten used to the idea of the newer program, but that is a possibility. More likely is that the name Family Tree will appear on the menu, but the two programs will remain connected for the time being.