There is no official date for PS3 release as yet, other than a comment from Yoshi stating that it IS coming.
Personally i think it would be foolhardy to release the game to PS3 until it is fully fledged, as a lot of sales will be resting on the PS3 release to rejuvinate the games playerbase.
If it is released to PS3 before it is totally ready, it could spell disaster for the games future, and i for one hope the future is bright