Rumor has it that Sony has designed a newer, slimmer play station 3 in hopes of boosting console sales. No one really knows if there will be any additional modifications to the system and most believe that just the design will be different. The previous version, Play Station II, has outsold the newer one by a couple hundred thousand, and Sony hopes to change that, hence the need for a new design.
Some of the reasons for this speculation are that countries have been noticing significant price drops in the PS3 consoles (perhaps in hopes of clearing out inventory and making way for the new ones) and there have also been a few leaked pictures of the device, as you can see here. Some believe it will be released within the next couple of months, just in time for the holidays.source of this post