[nxn]

I think it was a combination of things. One, the timing was nice because JavaScript was getting more and more attention as its engines were starting to seriously compete for speed. Two, I think the fact that it was JavaScript on the server really helped get it a lot of buzz as it was somewhat "controversial". "Controversial" because I can't think of another language whose users are so split between liking and hating it. Having it invade the server meant a lot of people's blood began to boil as they thought of having to potentially deal with it outside the browser, and a lot of other people who were excited about being able to use it outside the browser. Either way, the combination of love and hate gathered a lot of talk and attention in my opinion.

Now to contrast this with python: I personally have never heard of Twisted before all the talk of Node came about. Mind you, I'm not a python developer and if someone's blog title doesn't grab my attention by having some connection to me, or what I do, I'll probably just skip over it.