You stated imprison him until he discloses his source, but that has to be pursuant to a criminal investigation where he's ordered to testify. In the Plame affair, there's clearly no law broken. Here, we don't know if there was either.
Let's not repeat the Fitzgerald mistake: assume, then investigate. As stated earlier, let's also first see if what he published is actually correct. It would be a first if it were.
Again, the underlying and stated assumption is that 1) The President was acting in a lawful fashion when he authorized tapping into some Domestic communications and 2) From that, the person who leaked the fact of this activity was disclosing secret, substantial intelligence methods/processes and 3) They leaked to a reporter who then reported it in the NYT.
The reporter had the right to report and his reporting breaks no laws that I am aware of. On the other hand the Courts or Prosecutor could determine that laws were broken by the reporters source and could obtain an order requiring disclosure of the source or imprisonment for contempt.
We could disagree about whether the reporter should ever be compelled to disclose a source (I think if it can be conclusively demonstrated that laws were broken they should) but this is how I see it possibly playing out - And I would very much like to know his source.