It's The Planet. I have two servers there and both are up, but TP actually has 6 different datacenter networks in Dallas (last I checked, anyway), so that doesn't necessarily mean anything. But searching Twitter for @theplanet during a Planet outage usually leads to all sorts of evidence of an outage, and there's none at the moment unrelated to Linode.
We have nodes in all 5 Linode data centers. Currently only the Dallas node is down. We document all outages here: http://cloudharmony.com/status (click on the Linode links to view previous outages and outage documentation). Atlanta has been the most reliable data center for us (no outages in 6 months we've been up there).
Dallas seemed to be a problem for mosso -> Rackspace Cloud Sites, too. Just setup a linode in Dallas for a client last week, too. I hesitated to use Dallas, but I thought surely I was being irrational. It's still probably true that I was, but dang.
Yup. My server in Dallas is down. However, my server is New Jersey is still up and running. Are there any other server locations down other than Dallas?
Right now, http://twitter.com/#search?q=linode seems to be the best way to get information.
My linode is unreachable and pinging my linode's IP gets 100% packet loss, so it's not just DNS or anything.