The new site is working for a lot of people, but some Filers report they are unable to see the site at its new host, getting error messages, or receiving the last save prior to the move. My best guess is the internet services they connect with have not yet copied the updated DNS.
My new ISP’s Knowledge Base gives this overview of DNS propagation:
DNS propagation can be thought of as the time it takes DNS records to expire on a server. For example, if you update your nameservers to point to a different hosting company, those new nameservers must propagate across the Internet. Each ISP has their own time frame on how often they update/expire their cached DNS records. Because there is no single shared standard throughout the Internet, this entire process can take from a few hours to up to 72 hours.