holy fooooooooooooooooooook! The real Satoshi returns
Looks legit to me.
I think the age in the blog is Satoshi's real age. 38 sounds correct with the C++ language style he uses.
Now of course, Google (who owns ning) now knows where that post came from.
Would have been better is he signed it with his PGP key (or the private key for the coinbase reward in the genesis block

).
You mean the key for the alert system. He gave that info to Gavin, so there's no evidence that its him if he did.
Not the alert key, also IIRC the alert key has been changed.
The genesis block has a coinbase tx.
https://blockchain.info/block/000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26fSatoshi's very first wallet would have the private key for address
1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa.
A message signed with this private key would be the strongest proof possible. It is the only block which is absolutely known to be mined by satoshi.