It's been more than 10 days now, and DNS changes still haven't been propagated for some people using AT&T (but since 4 days ago, it's showing up for at least one AT&T user that it wasn't before).
Updated DNS to point to a new IP address (switched a server within the same host).
People are seeing the new website almost everywhere, but several people are still not seeing the new site after 6 days. I am one of them. My home AT&T connection is not updated and at least one other person that reported this also uses AT&T.
I checked with the hosting company (softlayer) and they confirmed that the DNS settings are configured correctly. They said there's nothing I can do but change the TTL and wait.
OpenDNS also has not updated the IP address for their New York and Washington DC locations, according to this page. (sometimes it shows the correct IP addresses, sometimes it doesn't)
I've never seen this before. Does anyone have any suggestions?