I don't know if this is quite what you mean but I've been doing something like this for a couple of years now and am bringing in decent revenues doing it. One example: http://javascriptweekly.com/ .. and an actual issue: http://javascriptweekly.com/archive/96.html .. I have almost 80,000 subscribers to publications like this now and people seem to keep wanting more (so I'm looking for and bringing in expert curators, as you suggest, since I'm close to exhausting my topic range).
Initially it was because I run/ran the most popular Ruby blog so the first couple of thousand subscribers came almost exclusively that way - http://peterc.org/blog/2010/306-1120-subscribers-in-2-days-m... - but since then it has been primarily a case of word of mouth and "domino" growth.
For example, many Ruby developers are into Rails. And many of those are into JavaScript. So I branched out into a JavaScript newsletter too and had a few thousand subscribers quickly. Nice (and unsolicited!) words from people like Steve Souders and Paul Irish helped with testimonials and it grew from there.
The next domino was HTML5 which was of interest to both JavaScript and Ruby people. So that one has grown even more quickly. And so on.. :)
