I am actually doing something very similar to this with Aether, but it runs on Qt, which offers far superior native platform support, Python in backend, and Angular.js in frontend. If there is any interest, I can extract this workflow from the main app and release it. Aether[0] itself is available here [1] too.
Kudos for you for similar thoughts, but you'll missing some points (or correct me if this isn't meant to be offensive...):
1. The "Trick" of the node-webkit based skeleton is, that frontend-developers must no longer think in terms of "frontend" and "backend", and therefore do not need to use different languages/libraries for different parts of the application. And: python is not that common among frontend developers.
2. NPM is just superior to pip.
3. I can't see any hint on your given links that you have a tech that is aimed at building crossplatform desktop applications without hassle and with maximized productivity. Maybe you should market your project differently.
I think I phrased the parent comment badly— Aether isn't the project, it's a project on my own in which in the building process I came up with that Python + Qt + Javascript stack. I was saying that if there is enough interest, I can extract that stack from Aether, and make it an open source bootstrap framework on its own.
1) You will always need to think about the backend, whether be it in Javascript or in whatever else. Using the same language helps of course, but Python and Javascript is a nice combo, too.
2) Virtualenv + Pip is pretty magnificient, but I don't have enough experience in npm other than the usual 'npm install ...' so I won't comment on this.
The point of node-webkit is, that you do not have to think about a backend. Really. If you are in the middle of you angular app and want to read a file, you just have to
require("fs").readFile("myfile.txt", ...
directly in-place. You can query databases, do requests, and so on without any problem and natively inside your angular app. Everything that node.js could do, which is everything a webserver could do.
And, in combination with NPM, you have everything you ever need just a `npm install ...` away for direct use in you angular app.
[0] http://www.getaether.net
[1] http://github.com/nehbit/aether-public