If I were suggesting anything at all, it would this:
* Continue to be civil.
* Avoid exaggeration.
* Stick to facts and irrefutable numbers.
* Before posting anything, read it over and ask, "Is any of this simply my opinion? Can I honestly back this up? Is there any evidence to the contrary?" If the answer to any of those questions is not a very solid "No," then now is not the time to post what you've written. Save that for later.
Keeping all of those in mind, feel free to let a little of your anger start to show. I realize how difficult it is to be civil and avoid opinion and hyperbole when sitting at the keyboard angry, but as long as negotiations are still ongoing, walking into the conference room, flipping the table over and walking back out of the room won't be helpful at all. Remember: even if we can't save City of Heroes itself, we still might be able to help save at least a piece of of Paragon Studios (under a different name, I'm sure) so that we can maybe help a few people get their jobs back and let them bring us something new and awesome to throw our money at in a few years.
Let them see that we are very unhappy with their company, show them your anger, but do not let loose your wrath.
The posts I've seen today on Facebook (linked above) and the "Fool Me Six Times" comic that appeared today were what I would consider good examples of how to do this correctly.