FIFA's report on possible corruption in 2018 and 2022 World Cup bidding has turned up very little. Most notably, it has cleared Qatar of any wrongdoing and a re-vote on the host of 2022 World Cup has been ruled out.
The United States also bid on the 2022 World Cup and finished second in voting. There was some hope that if the report found Qatar to have won the right to host by nefarious means, a re-vote would be issued and the U.S. could win, but that won't be the case.
Unfortunately for those who wanted to see Qatar (or Russia for 2018) stripped of the right to vote, it wasn't as if the report proved that the country's bid committee had acted correctly. The entire report was essentially about how the investigation could not turn up enough evidence to prove that they had done wrong because so many people refused to cooperate. Of course, FIFA could have helped pressure everyone involved to participate, but it appears as if they were very selective about who they would pressure.
Maybe the most damning thing that the report turned up was that Mohamed Bin Hammam -- a Qatari who used to be Asian Football Confederation President before being banned from FIFA for corruption -- was apparently found to have broken a slew of rules, but the report argued he didn't have a strong connection with the Qatar bid and did not work with them. That may be believable if the chairman of the Qatar bid hadn't previously praised Bin Hammam for his work on the bid, working with them and calling him "definitely out biggest asset on the bid."
And before you think that is the worst thing to come from the report, keep this in mind. The man who conducted the investigation which the report was based on has called into question the report, saying it is incomplete and misrepresents the investigation.
The good news for the U.S. is that they have been found to have acted about as ethically as possible. The closest thing to a condemnation of the American the report turned up was an allegation that the U.S. brought up the possibility of China hosting the 2026 World Cup and how that would affect future World Cup bidding.