unless that AMD "leak" really was related to Nintendo afterall (which hardly seems possible since IBM is doing the CPU).
Which AMD leak? 'Cause AMD bought ATI, who made Nintendo's last two graphics chips, so both AMD and IBM are probably involved in Wii U. Was the leak about CPU specs specifically?
This rumor
http://www.nintendoworldreport.com/forums/index.php?topic=32855.msg645130#msg645130and this rumor (March - no link, I didn't want to out the source and possibly get him fired)
http://www.nintendoworldreport.com/forums/index.php?topic=16688.msg676207#msg676207It was basically that an AMD employee mentioned that they were working on a "Fusion" based chip for a major console that was to be ready to ship by the end of 2012. He said that they were told to push the schedule forward to earlier in the year, so now they were in sort of a crunch time at work.
He didn't specify which of the 3 it was and since we all assumed that AMD wasn't fusioning an IBM CPU with an AMD GPU for Nintendo, that it must have been another chip for MS. That is when a lot of speculation that X720 was gonna launch at the end of 2012 to compete with Wii2 (now known as Wii U) was going on.
It also has to be known that (AFAIK) the Xbox Slim redesign was a sort of "fusion"ing of the AMD GPU and the IBM CPU onto a single chip reducing the power draw and improving the overall performance of the chip since it was now done at a smaller fab process.
With rumors that Xbox720 isn't coming till atleast 2013 and maybe not until 2014, I guess it could be possible that a joint effort between IBM and AMD could produce a "fusion"ed chip for Nintendo. But the supposed "leak" hasn't been proven in any way and the original "leak" hasn't commented on it since. So who knows what's really going on.
Also IBM already stated that they are doing 45nm for the Wii U GPU and AMD is pushing for something that is likely much smaller than that (hopefully 28nm). So I really don't see the Wii U being a mixed nm SoC... but I don't know if that is even possible or not.