It seems to be http (perhaps load balancers) rather than the instances being down - I'm ssh-ed into a droplet and everything is working fine, except remote HTTP connections.
I ssh-ed into some droplets, but others are completely inacessible outside DO. The internal network works fine, so it is just a several network outage. Again.
It seems to be intermittently up and down. So your connections all die, and you can't reconnect for a while, then it comes back and everything looks good for a bit until it dies again.
http://netalyzr.icsi.berkeley.edu/cli.html