1. Cohen provides plenty of smoke - if not a gun

Cohen gave key claims and documents that will birth all kinds of new targets for reporters and, potentially, investigators. But most of his most important contentions require explanation and inquiry.

His statement that he heard a phone conversation in which President Donald Trump spoke to Roger Stone about a looming WikiLeaks documents dump before it landed? We still need to know exactly where Stone allegedly got that information and whether it actually came from WikiLeaks.

The scene he painted of Donald Trump Jr. whispering to his father, "The meeting is all set," around the time of the Trump Tower meeting with a Russian lawyer? Trump's knowing about the meeting would be significant, but that's hardly conclusive on the basis of what Cohen says.

Cohen's statement that Trump's lawyers altered his testimony about the timeline of the Trump Tower Moscow deal? It's important to know in what way - and whether they were acting at Trump's direction.

Cohen suggesting Trump inflated his assets while applying for a loan from Deutsche Bank to buy the NFL's Buffalo Bills? There are many ins and outs there.

The big takeaway here, as it has been in much of the investigation by special counsel Robert Mueller III, is that there is a lot that we don't know, and it might have been investigated far more than we're aware.

2. The other investigation

Speaking of which, in one exchange with Rep. Raja Krishnamoorthi, D-Ill., Cohen hinted at another investigation involving Trump. And he said it involved Trump's breaking the law.

"Is there any other wrongdoing or illegal act that you are aware of regarding Donald Trump that we haven't yet discussed today?" Krishnamoorthi asked.

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Cohen responded: "Yes, and again, those are part of the investigation that's currently being looked at by the Southern District of New York."

This would seem to be separate from the campaign finance violations to which Cohen has pleaded guilty (and in which he implicated Trump) and which had already been chewed over in the hearing. It also would not seem to be the SDNY's probing of the Trump inaugural committee, which had also been broached. And it would be separate from anything having to do with the Mueller investigation, which is not being handled by the SDNY.

The most tantalizing prospect is that it might have something to do with the Trump Organization, but we have no idea.

3. The times he defended Trump

If Cohen was there to take down Trump at all costs, as Republicans warned he was, he sure passed on a few opportunities.

He contradicted a BuzzFeed News report that Trump had directed him to lie to Congress, saying the direction had been more implicit than explicit. And he shot down a McClatchy report alleging that he went to Prague in 2016 to coordinate with Russians about the election, a key claim in the Steele dossier.

But it wasn't just that. At one point, he was asked about an alleged tape of Trump in an elevator in which Trump hit Melania Trump. Cohen said he had tried to establish whether it existed and found that it didn't. He said, too, that whatever he thought of Trump, that kind of behavior wasn't in his repertoire. "Mr. Trump would never," Cohen said.

He also disputed another allegation, for which a former Trump employee was paid $15,000,

4. Two questionable claims

There were two exchanges in which Cohen seemed to contradict the public record, and where he might have to explain how his statements are consistent with the facts.

He was asked on multiple occasions whether he had sought to work in the White House, and he denied it. "I did not want to go the White House," he claimed. This is at odds with reporting, including by The Washington Post and the New York Times, indicating that Cohen had sought jobs at the White House but failed to land any. The Post reported that he had been in the mix for White House counsel and had even promoted himself as a possible chief of staff.

Cohen seemed to acknowledge at another point that this had at least been run up the flagpole and that it was decided that he would be forfeiting his attorney-client privilege with Trump. "I brought a lawyer in who produced a memo as to why I should not go in because there would be no attorney-client privilege," he said. "And in order to handle some of the matters that I talked about in my opening, that it would be best suited for me not to go in."

Another discrepancy involves Prague. He has denied the claim, and here he did so again, this time under oath. But he went even further, saying, "I've never been to Prague. I've never been to the Czech Republic."

Except he told Mother Jones's David Corn in 2016, "I haven't been to Prague in 14 years. I was in Prague for one afternoon 14 years ago." And he told the Wall Street Journal he was in Prague in 2001, so around the same time. Did he mean he was only there briefly? Is that the same as never having been there? Expect to hear more about this.