I see a lot of disagreement with this post but I think it makes good points. It's hard for small developers who make useful things to get noticed on GitHub. The only hope is to get retweeted by some established user. This seems silly, we need better ways of making sure people can find/discover good software.
Although they've added plenty of trendy social network-y features that's what it is as its core.
There's no silver bullet for "getting noticed" whether on Github or outside of Github.