I don't see the point in this. NaCl isn't about showing how slow JS is, it's about allowing people run code written in C/C++ with a recompile plus some glue code.
Totally different matters. People forget how much C/C++ code there is out there. Nobody is going to rewrite it into JS.
The comparison between this and NaCl is quite a stretch. NaCl has much further ranging implications -- being able to code in any language and having it display in the broswer is a true paradigm shift.
JavaScript is the only possible standard. Here's why:
Apparently, the world need a Turing complete Web, so it can be used for things totally out of its original scope (publishing).
Technically, it makes little sense. It often wastes bandwidth, CPU, and efficiency of interaction. (Gmail is cool, but a native version of it could be better in all three ways.)
But, because people are idiots who don't know how to install a program on their machine, we need to give them a way to use such programs without even having to point or grunt before they get started. (Well, it's not a need, actually. That's a choice. Idiots can be educated. And they will be, eventually.)
To this day, the only Turing complete thing that is installed by default on every computer on this planet (meaning Windows PC and Macs) is JavaScript. Unless we displace it, and until "average users" educate themselves, I think we're stuck with JavaScript.
I guess I'm an idiot user for preferring Gmail to anything else I've used while getting the additional benefit of having that exact same interface on any computer I use without having to install anything.
I should have use scare quotes. I didn't want to say that users are idiots. They are ignorants, or just don't want to bother. What I did want to say is that most developers do take users for idiots. Software that doesn't need a manual and takes 5 minutes to assess is made for idiots. A nice side effect is that it works very well for everyone else.
Now, using Gmail won't make you an idiot by itself. But it may be an idiocy, depending on whether you know what you are doing or not. By default, I strongly suspect that you don't. Here's why:
First, there's the obvious privacy issue. Much of your private correspondence is stored on Google's servers. Google makes semantic analysis on your e-mail, so it can send you ads. They could do many interesting things with your e-mail if they want to. They are an interesting target for internet based attacks. They could make mistakes that affect all users. Do you really trust them that much?
Second, there's network issues. Web based mail is hurting the network in two ways.
The first is that their ubiquity lead people to believe that to send e-mail, you only need the 80(http) and 443(https) ports. Thanks to that almost nobody noticed, or cared, when ISP began to block the outgoing 25(smtp) port. They pretended it was to prevent their customers to send spam. Because they took them for idiots whose Windows computers are full of botnets. They may be right, but the real effect is that their customers can no longer send e-mail by themselves, and have to rely on third parties instead. That makes web-based mail much more attractive. The loop is closed.
The second network issue is the way data flows: from Gmail to your ISP's network, and not the reverse. The effect is even more pronounced with sites like YouTube. This asymmetry, which you could have avoided if you ran your own mail server and hosted your videos yourself[1], makes hard for your ISP to get good peering agreements. And now, they invoke this asymmetry to argue that "content providers" should pay to send their data.
[1] Oh, you can't. I forgot the "A" in "ADSL". Sorry.
Anecdotally, don't you find silly that all your e-mail goes through the silicon valley before it reaches your neighbour? That's not very efficient.
As far as I know, JavaScript only serves 2 purposes: eye candy, and doing remotely what could have been done locally (meaning using web apps). Both purposes are dangerous idiocies (without quotes, this time). Using a Turing complete thing to do eye candy is idiot because of the needless potential security breaches. And using web apps is idiot because you lose control and help creating an unnecessary centre. (Note however that doing web apps is not idiot at all. See Facebook.)
The current trend of webifying and centralizing everything terrifies me. If we don't pay attention, they will shut the internet down. No server at home, only clients (preferably webkit based ones). And what could have been the voice of the people will go back to the propaganda of the powerful.
Totally different matters. People forget how much C/C++ code there is out there. Nobody is going to rewrite it into JS.