One concern for democracy is a too powerful and biased press. I suspect that this is less problematic than it once was, as our news comes from increasingly diverse sources: print, terrestrial TV, radio, satellite TV (including foreign channels) and the Internet. Indeed, it is now far easier for anyone with a connection to discover blogs on virtually any subject and to access raw data on many aspects of society and government.
Perhaps the next media mogul is Google, but it doesn't have a monopoly - there are still a number of good search engines out there and they only cover one information channel making them a little less controlling than the press Barons of old.
Newspaper readership figures can be found here.