Google has implemented a setting that allows users to choose the frequency that blogs and press releases appear in their search engine results pages. Regarding news worthy blogs, you may want to ask Google to consider reclassifying your blog as a news source.
The settings for this feature can be found on the Google News settings page:

You’ll also find a new setting that tells Google to refresh blog and press release pages every fifteen minutes.
If you’re ready to “stop being a blog,” you can submit this form, and Google will consider your request.  Google is evasive about saying what exactly they, by default, consider a blog. It seems as if RSS content will put there right out of the gate.
What we do know is that in September of 2009, Google said to use the aforementioned form if you’d like to be reclassified, or felt as if you were “misclassified.” A preview of it is shown below: