You are right on all points ebiester, but you missed the one compelling reason to use node anyway: the browser is well on it's way to being the dominant programming model (and for a good reason: application components and data are addressable by other applications via the DOM! this turns out to be necessary to have globe-spanning meta-programs like search, and also useful personal meta-programs like Evernote) and that model can and will extend into the server. JavaScript is a quirky language but can and will get's it's act together. "use strict" for example was a good step in the right direction.

Even more than that, I think that the entire notion of what a server is for is changing rapidly away from "server-side MVC" to a far more rational (not to mention more efficient) dual role of "initially serve a client" and then "handle messages from the client". Server-side manipulation of client state is a horrible, terrible idea in any language, and right now node is suffering from cultural/technical momentum of wanting to do things that way. Once that impulse goes away and alternatives become more popular and well-understood, I think node will get even more popular.