It was recently announced by LEGO and WB that a LEGO HP game is scheduled for a 2010 release alongside the final two HP films.
The game has also just released its first offical teaser trailer. In the trailer, it shows that the game is based on the first four books/movies of the series. And if there are going to be eight HP movies, a sequel to the game is expected. Few offical snapshots or posters of the game have been released yet, nor has there been an announced release date. the trailer is avalible through this link: http://www.amazon.com/gp/mpd/permalink/m3FVLHD72HO2LM/ref=ent_fb_link .
The game is said to be avalible on these systems: Nintendo DS, PlayStation 3, PSP, Nintendo Wii, Xbox 360, and PC.
No Spicific release date has been announced as of now.
The game is, however, avalible for pre-order from retailers like amazon.com .
More information concerning the game is expected closer to its release.