News articles can be included in existing layout, if you mean like putting "latest news" or some other selection of news to the homepage of your site. On the other hand, full software cannot be included in existing layout as-is, the layout (HTML files) need to be converted to templates (.tpl) files prior to running the software. This is rather straightforward process, and we can do it for you if you wish.
The newsgrabber already exists as some sort of customization we did for couple of clients so far, and we can do it for you as well.
We gave some thought about including this as an standard feature in release, but we faced couple of problems that kept us from doing it so far. People want totally different news sources, there are some copyright restrictions to most of them and we do not wish to be legally responsible for releasing the software that allows that, etc etc...
As for the trial version, we do not offer one however you can test everything out on our Playground server (http://playground.word-press.net
), and access it as Administrator from the Demo page (http://www.word-press.net/demo.php