As much as I hate being the messenger on this one, it's got to be said: Criterion Games is finished putting out post-launch content for Burnout Paradise. It's understandable if talk of the canned add-on ideas got you all fired up, but it's not going to happen. Burnout on the moon is nothing more than a pipe dream.
Apparently, fans have been after the studio for some time now. Take a look at this recent tweet: "Please stop asking us for Burnout Paradise DLC. There will be no more! Sorry everyone! But we did WAY more than everyone else ..."
If anything, you guys should be going crazy with the Need for Speed questions. Perhaps you'll get a vague answer, perhaps you will further annoy the good people at Criterion. It's a chance you need to be willing to take.
Criterion: "No More Burnout Paradise DLC" [TheSixthAxis]