Slide interval = 1 day. This way Grandma could awaken each day to a new picture to enjoy on her iGala. I have been waiting for this feature ever since photo frames were a new idea.
Everyone (but me, it seems) appears to be stuck on the idea that there has to be a rapid turnover of photos. Think outside that box!
It is already done and available
Please go here to get the latest firmware update and it contains the new feature that will allow the update frequency of 24 hours for the slide show transition.