Can’t you just export a vector file and then let whatever other renderer (e.g. a browser) handle the antialiasing?

Edit: I don’t think I understand your complaint. The graphics in the original article are antialiased. Are you just saying their antialiasing algorithm isn’t as good?

Here’s what your version (on the left) looks like when rescaled (using Preview on OS X to rescale) to about the same size as theirs; the two seem roughly comparable: http://i.imgur.com/LWCeAPj.png

(I think the reason for the difference in apparent line/font weight in my picture there is that Preview properly downscales in a linear (not gamma-encoded) color space, whereas most vector antialiasing/rasterizing algorithms, including both Quartz and Cairo AFAIK, work in a gamma-encoded space). If you had generated the image at the same original size, I suspect it would look extremely similar to the one in the blog post.