That was then, this is now. It would scale up to 1080i.
Look at page 414 of the thread I directed you to. It is filled with people who are confirming that it scales up to 1080i. That thread is THE source on the matter. It is very well maintained and more reliable than the back of boxes.
http://boardsus.playstation.com/playstation/board/message?board.id=ps3&thread.id=1543693&view=by_date_ascending&page=414
Uncharted was released last year before the developers were providing upscaling abilities to their games. EDIT: The PAL version of Uncharted is 720p Only. NTSC Version does do 1080i.
EDIT: Always keep an eye on the following post since it is always updated:
http://boardsus.playstation.com/playstation/board/message?board.id=ps3&message.id=1543717#M1543717
