1. 'might' implies the future. As you can tell from the post you're replying to, Systemtap is present thing. I think I actually put most of the tapsets shown on the Wikipedia page around 2009, and I was using them then.
2. Also, as the author partially acknowledges in the next slide, Ubuntu is the dumbest place to illustrate a typical Systemtap experience. I suspect that's deliberate, rather than ignorance as Sun tried that a few years back and I don't think anyone with any interest in the matter is ignorant enough not to remember the shitstorm.
As I've written elsewhere: if your customers mostly run Ubuntu, then test dtrace on Ubuntu too. It'd give you just as accurate impression about what the dtrace 'experience' is as installing SystemTap on Ubuntu.
Edit: actually looks like Joyent wrote the shitstorm post for a few years ago, you've still got it up, you still don't see anything wrong, and you just linked to it.
christ read the HN comments from 2011. https://news.ycombinator.com/item?id=3118416
Edit 2: you're Bryan Cantrill. You didn't seem to care much about performance a while ago: http://cryptnet.net/mirrors/texts/kissedagirl.html
Edit 3: more Cantrill classiness http://www.quora.com/Node-js/Why-did-Ben-Noordhuis-decide-to...
Sorry to anyone who thinks I've gotten personal, but this guy is a well known... unsavoury character.