Update:

>>> this started circulating 5 days ago:
>>> http://img12.imageshack.us/img12/1228/prcspec13iu.jpg

>> How accurate do you think that document is? Could it really
>> be a Nintendo internal document or just an elaborate fake?

> We'll know for sure in a few days I guess.

We now know that this sheet must be hoax as it talks about a "32nm process" whereas IBM has to say:

"IBM plans to produce millions of chips for Nintendo featuring IBM Silicon on Insulator (SOI) technology at 45 nanometers (45 billionths of a meter)."
http://www-03.ibm.com/press/us/en/pressrelease/34683.wss

No information on core count (just "multi-core") or frequency, unfortunately. And Nintendo doesn't reveal any better info either:

"CPU: IBM Power®-based multi-core microprocessor."
http://e3.nintendo.com/hw/#about

So let's wait and see if the older triple-core rumour turns out true.