Tony Hawk's Pro Skater HD will be released on the 18th July as a part of Microsoft's Summer of Arcade, and the first batch of downloadable content will be hitting a month later.
The DLC will feature additional levels from the Tony Hawk titles, one of which is the Airport Stage from Tony Hawk's Pro Skater 3. The DLC will also include the ability to do the "revert" move, which allowed players to do some special combo strings.
The content will cost 400 Microsoft Points ($5 USD). There is no word of when the PSN version might be released.