Apple would never be able to take over Sony or vice versa although theres always the chance they could join together - as you say they have very few products that clash (only the iphone/ipod touch versus PSP). They both have a illfondess of Microsoft XD.
I wouldn't be surprised if Apple started developing games though instead of annoucing their own console.
Richard
<a href="http://eu.playstation.com/psn/profile/cleaner475/"><img src="http://mypsn.eu.playstation.com/psn/profile/cleaner475.png" border="0" /></a>