Update August 14, 3.45 pm ET: Activision has since put out a further update reminding PC players that they will need to have TPM 2.0 and Secure Boot enabled on their PCs to play the Modern Warfare 4 beta. This is the current requirement for Black Ops 7, so it isn't new, but it's a reminder if you haven't been playing this year that without it you can't take part.
Mark your calendars, Call of Duty fans, because Infinity Ward and Activision have revealed the content of Call of Duty: Modern Warfare 4's upcoming beta tests, set to commence over the following weekends.