So the long wait is finally over. Ponyo on a Cliff by the Sea will be the first Studio Ghibli feature to arrive on Blu-Ray. The release is currently scheduled for December in Japan, and I would expect it to contain all the features of the standard DVD versions. Goodness knows there is ample room on the blue discs for everything.
The best part for the West? The Blu-Ray standard uses only three global regions. Japan and North America belong to the same region. This means you can import this Blu-Ray, or any release from Japan, and it will play on your machine without any problems.
No doubt, we will see the Ponyo DVD and Blu-Ray here in the USA either late this year or early next. The window between a theatrical and home releases are continually shrinking, so I don't expect Disney to sit on this movie for very long. At least, that's my own gut feeling for now.