Thanks, I spent a minute skimming through this post and ended up coming here hoping someone wrote a tl;dr like this. Must be challenging to write effective copy for something like this (not being sarcastic)
One interesting bit from the article: "Does this mean that I'll be able to DTrace my Linux apps in a Docker container?" (yes)
Technically you can run dtrace on various platforms, and I don't know enough to tell you specific reasons why you would rather use dtrace on smartos than linux. I got the impression a few years ago the ports weren't as good. (perhaps relating to the linux port not yet being a kernel module?)
"A gritty how-to on debugging LX branded zones on SmartOS presented internally at Joyent on 1/30/15. While given to an internal audience, there is quite a bit of information here that may be interesting to the broader community"
I haven't heard of this before today, but it seems as though with this you could scale out to multiple servers and it'll continue to be treated as a single docker host. It also isn't linux.
Triton lets you run your docker containers in the cloud without worrying about virtual machines or setting up your own paas.
Signup here: https://www.joyent.com/lp/preview