Possibly the bigger issue for users of private mode in Firefox is that extensions are run: Users have to trust that extension developers implemented private mode correctly. In Chrome, extensions don't get to run in private mode, unless the users allows them explicitly.
I completely agree. It also seems the list of programs that were analysed is not quite as diverse as one might wish. It'd be great to see what some other categories of software might use. For instance, I could see OpenOffice to be an interesting application to look at.
I am very excited about this one. On the web we have JavaScript, which is an open standard and works in some circumstances, but applications that need low-level, efficient languages are left with no good alternative. People have tried to push various alternatives like Silverlight, Java Applets or Flash, but none of them are open. With Microsoft, Google, Apple and others working on WebAssembly, we might finally get a low-level language for the web that is open!