What Comey is mostly going to do is obfuscate and insinuate. Truthfully the only thing he is going to be doing today is come up with carefully manicured quotes the press can take out of context.
It's going to be a nothing-burger from a less-than-nothing-burger.
The press will act like this is an all important, Watergate-style presidency ending event. They will try once again to work themselves into a full on SJW lynch mob. And will all come to nothing as the president will simply ignore their antics.
Although it will give Team #NeverTrump yet another chance to shake their girlish fists while writhing in their own insignificance. Looking at you Justin Amash and John McCain.
The part the press doesn't get about Watergate is that it simply wouldn't happen today. There was a reason they were able to bring down a president. The press had an ill earned reputation for impartiality, if not actual honesty. That sure as fuck ain't the case today. The press doesn't have the power it once did because no one on the Right believes them anymore. Truthfully the Left doesn't believe them either because a pig identity one its own by the smell.
Comey is a lying sack of shit who lies by telling veiled half-truths. He has a mindset only a Washingtonian could love
So far as I'm concerned firing Comey is up there with appointing Gorsuch. An incalculable service to the republic by the God-Emperor.
Comey now begins his well deserved voyage into obscurity.
UPDATE: It was even duller than I was expecting. His entire testimony came down to "Trump asked for his loyalty; Trump said he hoped Comey could let the Flynn matter go; and Trump was, just as Trump said, not the subject of an investigation."
UPDATE 2: It is really time for McCain's family to hold a competency hearing.