I'm not quite up to date on the latest, but Hannity has had a series of "I didn't inhale"-esque explanations for this (something like "I'm not his client, except I am, except it, was just advice, but still subject to attorney-client privilege, " etc...) Given what work Cohen did for his other two clients, one can only wonder what is going through the mind of Mrs. Hannity at the moment...
In any case, it seriously calls into question all of the last weeks or so, where Hannity went to the air attacking the raid on Cohen like a bloody madman, saying that Mueller had “declared war against the president of the United States" with this. It's unethical as all hell, and just as importantly it looks very bad indeed... the scandal has entered a new and interesting phase.
Meanwhile, the internet exploded with all this: conspiracy theories are the order of the day. Top theories include that Cohen was the go-between of Trump and Hannity, relying on the power of Attorney-Client Privilege to protect them; which might have worked, if they hadn't gone and made such a big deal of trying to not disclose who his third client was. Supposedly they used every trick in the book, claiming that it was embarrassing (no shit...), at one point just asking if they could just give it to the judge without unsealing the envelope, etc. Judge wasn't having it.