[thewanisdown]

We have an internal website with user-maintained groups/content. Every week, you get an email with major updates from the teams you want based on the important information they've been telling themselves. That's been useful for culling and focusing the information flow to each person.

In my experience, newsletters don't work well for internal communication. As you said, keeping the content relevant to a wide readership is too difficult. It does, however, work well as a recognition mechanism. A team seeing it's achievements blasted out to the company is very motivating, even if they are the only one's who notice it.