In the early days (2008/2009), a couple people I know got apps featured in the App Store. Basically, they got a call out of the blue from Apple.

Now, it seems that it is back to good old fashioned relationships and community [1] and marketing. Media coverage, for one, being the most important. Media coverage goes a whole long way longer if the editor actually knows who you are (e.g. you met them in person and had a real conversation) and likes what you are doing.

http://realmacsoftware.com/blog/how-to-get-featured-on-the-a...

And they still probably get a call out of the blue from Apple. But not by dumb luck, by doing the work required and getting better and better (at marketing, community building and nurturing, the app, all of the above)

[1] http://www.kk.org/thetechnium/archives/2008/03/1000_true_fan...