You need a place to host the text of the press release so when each one is posted, it then can be read by most readers.
I recommended creating a Blog at Blogger and hosting the press releases there.
Then, each time you post, they can be read. The News Readers will have to subscribe to the Blog to read them, but you can promote that.
Then, go to FeedBurner and get a upgraded Feed address so your subscribers have more options.
Each time a writer submits to you a press release, you can show them how to read their own feeds using FireFox or Bloglines.
I'm not up to date on the Vista yet but it may also be able to read feeds.
Once all your writers know your feed URL, they can also promote it by letting their contacts know how to subscribe and know when they have a new product.
I hope this is helpful. I recommend Blogger because they create a feed address for you. You then can use that address at FeedBurner.
Let me know if this helped.