He has a colorable claim but no chance of winning. The founder of a cryptocurrency which now boasts of a >$1 billion market is legitimately a matter of the public interest, even if it's not the right guy.
This principle has been established many times by people who were mistaken for criminal defendants (not always defendants with the same name), including the Boston U student who killed himself shortly before the Boston Marathon bombing.
"Legitimate public interest" is a defense to a tort. It is used by the publication to defend itself from an invasion of privacy claim. It can't be used by a plaintiff (except as a defense to a counterclaim by the defendant).
That's it, it's a slam dunk case Newsweek is liable for bajillions of dollars. He sure didn't act like a secretively paranoid inventor of bitcoin.
I bet newsweek would love to see his entire email history. He should probably sue them so he can see that email to the merchant and newsweek can read his entire email history, as well as subpoena various other people for their private emails with satoshi. This will be a winning legal strategy to protect his privacy.
I wouldn't be so sure. Both may be subject to tort liability if Dorian Nakamoto != Satoshi Nakamoto. See my tweet: https://twitter.com/declanm/status/441711365888040960
And a response by an attorney who works on Internet issues: https://twitter.com/SeanFlaim/status/441727448539873281