I found a really interesting article today, all about local government and its use of English, plain or otherwise. I spend quite a lot of my time making government-ish stuff more readable on the web, so it was quite interesting to see how Derby City Council is dealing with the issue.
I find there's just no getting away from some usages of jargon - in some cases it's hard to see what you would use instead of phrases like ‘place shaping’, ‘community cohesion’, ‘sustainable communities’ and ‘engagement’ that the author rails against. In the right setting, they're very useful. Yes, they're ugly, but they're concise - and my other task is usually turning long, meandering sentences into something shorter and snappier.
In a web context, a long-winded description of 'sustainable communities' is probably going to turn more readers off - especially if they're scanning the page. What's nice about the web, though, is that you can direct reader to an FAQ or a glossary if they're unsure of the terminology (there's a nice example on this climate change website, where the definitions pop up on mouseover).
It probably doesn't look quite as good in print, however, if you have to issue a glossary with every letter that you send out...