There has been a big push over the last few years to develop what has been coined as "usable security". Things like drawing patterns on Android devices instead of typing in a 4 digit pin or identifying particular things in an image instead of typing a password have been developed. The biggest problem with these usable security mechanisms is that they often take longer to use than the alternatives.
Imagine if you had to take your mouse and click at 10 particular spots in an image every time you wanted to unlock your screen at work. Doing this would take several more seconds at every sign on and would add up quickly. Often for systems that are used often keying in a password is still the fastest method.
Well Microsoft has developed a new solution. Instead of having password requirements that are visible to the user, like minimum length, they want to let users use anything as a password. Even simple passwords like "love" would be accepted. However there is a catch, only a small number of users will be allowed to use a particular password.
Complex password requirements were introduced to combat spraying and braying attacks. A spray and bray attack is when an attacker tries to use one particular password on a large number of accounts. This way bypassing lock out procedures. This solution by Microsoft will fix this by only allowing a small number of accounts to be compromised and thus reduce the benefits of the spray and pray attack while keeping passwords simple and easy to remember.