Speed for right now...
It is taking a while for some DNS servers on the Internet to propagate the new site IPs, etc. (DNS servers basically direct Internet traffic and tell them what site marries up to what IP address...)
For example...
Your computer doesn't know what
www.yahoo.com means. A DNS server equates an IP address to that name (DNS stands for domain name server)...
The new IPs for the new server have to be "recognized" or propagated throughout the Internet, some providers do this very, very quickly...sometimes it can take a few hours....