Later this fall, you'll be able to download Burnout Paradise from the PSN store. The download will still cost $29.99, the same price as the boxed copy (you can probably thank your brick n' mortar retailers for this), though the version will feature all of the already released download packs, including the new Online modes, challenges and vehicles.
The download is part of the increased DLC support Criterion is bringing to Burnout Paradise. Over the next few months, expect to see even more new play modes and the addition of motorcycles, weather, a new island and day/ night gameplay.
No official date has been announced for the PSN download or new DLC, though you can expect to see both roll out before the end of the year.