The other day we got Gamercast listed on Google News, however we had a bit of trouble getting our news articles correctly indexed so I had to find a Google News sitemap plugin or skin for b2evolution.
After 30 minutes of searching I came up empty handed. So I just modified the existing _sitemap skin to do the job.
You can download it here.
There are a couple of things you'll need to do to get it working. First up you'll need to specify the publication name, language and any Google keywords in the file directly. I didn't pull this information out of the blog because the blog name might be different to the publication name on Google News, plus Google recommends specific keywords. So yes this may cause issues if you run multiple blogs on the same backend which you want listed on Google news, however as a workaround you can just use multiple copies of the skin. There's also some fields not used by the skin, such as the tags field or the subscription options.
You'll then want to upload it to the b2evolution skins directory into a folder of your choice, for example _newsmap. You can then check to see if it is working by visiting yourblog.somewhere/?tempskin=_newsmap that should show articles from the last two days. All you'd need to do then is submit if via Google's webmaster tools.