sign his PGP key or prove that he owns the wallet with 1 million bitcoins.
There is a 1 million btc wallet ??
No. Well maybe, but not in that it only contains one address. The estimated one million bitcoin that satoshi owns is split up into several thousand addresses.
I think he was saying that a single "wallet" like a multibit wallet or a blockchain.info wallet would contain the keys to all the addresses that contain the million bitcoin. (I would assume that the wallet would actually be a QT wallet)
