1. Blogger's voice
While most blogs can't be considered news sources and many news sites avoid to quote blogs, Google News could use Google Blog Search to show comments. Google could also separate positive and negative comments.
2. Using the archives
Google introduced News Archive, a service that expands Google News with newspaper articles from the last 200 years. But Google forgot to actually use the service. Some articles could be better understood if we read related news from the past.
3. More context
Use Google Search to find links that might help you understand more the context of the news. Google Related Links is a good start for that.
4. More interactivity
Some news are more valuable if you actually see images or videos that describe the content. Google made a deal with AP, to use full content of its news, including images, so that could be a good source for the images. Videos from news televisions, delivered using Google Video, could be the next logical step.
5. The wisdom of crowds
It's hard to understand if a news is important and if it is, to whom. A rating system and a way to keep to track of your favorite news might improve Google News homepage and its personalization system.
To sum up, Google News is a perfect place to integrate many Google service that could give a better perspective on the news.