This is the next in a succession of moves by Google to increase advertising across their services, ranging from sponsored videos on YouTube to ads inside Google Image Search, an extension of their standard search engine.
In all likelihood, the advertisements will probably be well-received by users. After all, there's little complaint about their ad situation currently. Where Google may receive quite a bit of flack, however, are the places they source news from. Like many conglomerate sites, Google relies on giants like the Associated Press to discover and replicate news. Those sources might want to squeeze something out of Google if they turn a profit on their news service.
Whether or not that's going to be the case only time will tell, but one sure bet is that Google's level of advertising is only going to increase as the company grows larger.