I'm not sure it's really driving news cycles, but I have vaguely noticed reblogging, even from high-profile bloggers (e.g. at mainstream newspaper/magazine websites) being keyed off stuff that gets big at Reddit, if not first, then at least before they blog it. I wouldn't be surprised if some of them are monitoring relevant subreddits for reblogging ideas.
You'll see something get a few hundred comments on Reddit, often in one of the non-default subreddits, then the next day there's an article on an Atlantic or NYTimes or HuffPo blog about it. It'd be interesting to trace who influenced whom, since I don't have hard numbers, and am not 100% sure where Reddit fits into the food chain. I'm certain there's some food chain though, because some of it is very unlikely to be coincidence; e.g. I'll read some interesting "weird historical episode" tidbit someone pulled out of Google Books one day, then a day later a mainstream news organization is blogging about this very same weird-news tidbit from 1913, which they clearly borrowed from somewhere (whether Reddit, Twitter, some kind of analytics data, etc., I'm not sure).
You'll see something get a few hundred comments on Reddit, often in one of the non-default subreddits, then the next day there's an article on an Atlantic or NYTimes or HuffPo blog about it. It'd be interesting to trace who influenced whom, since I don't have hard numbers, and am not 100% sure where Reddit fits into the food chain. I'm certain there's some food chain though, because some of it is very unlikely to be coincidence; e.g. I'll read some interesting "weird historical episode" tidbit someone pulled out of Google Books one day, then a day later a mainstream news organization is blogging about this very same weird-news tidbit from 1913, which they clearly borrowed from somewhere (whether Reddit, Twitter, some kind of analytics data, etc., I'm not sure).