>I'm not sure how common this is, but newswriting (a sophomore-level course) was the weed-out class for all mass comm degrees at the state university I attended. I went into a summer newswriting class with quite a bit of writing experience and it still had an impact on me.

Definitey. And reading good writing is also an excellent way to improve one's communication skills.

It doesn't even need to be related to subjects you might be writing about either.

Good novels, well written essays/non-fiction books, etc. can provide examples of good writing and, if one continues to read well written stuff, it will likely rub off.

That's not a substitute for your suggestion (which is a good one), but another way to improve how one communicates in writing.