Last year when Google launched Allo and Duo, their new messaging and video apps, the company confirmed that Hangouts wasn't going away, and that it would transition into an Enterprise product. Well that transition may have kicked into high gear today with the launch of "Meet". But it does also appear to have launched a bit prematurely. Seeing as the website doesn't really do much of anything, at meet.google.com (also it automatically switches you to a G Suite account). Additionally, the Android app is not available yet on the Google Play Store, but it is on the Apple App Store for iOS, surprisingly enough.
There's not a whole lot known about Meet just yet, but from what we can tell, it appears to be very similar to the current Hangouts that's available. Although it does seem to be a bit more focused on video calling and video conferencing than actually messaging like most people use Hangouts for today. It works a lot like Cisco, which is a popular product that a lot of companies use for online meetings. Where someone could create a meeting and others could join by using the code that they were provided with (this is also so that random people don't jump into your meeting, which has happened with Hangouts in the past, actually).
At this point, Google has not made anything official about Meet just yet, but it is likely only a matter of time before it becomes official. It wouldn't be surprising to see Google make it official tomorrow, as they were likely waiting on Apple to approve the iOS app so that they could launch on Android and iOS simultaneously. Meet looks to be a replacement for things like Hangouts on Air, and if it is done right, Google may have a pretty good competitor to something like Cisco and Skype. Both of which are already widely used by companies. But with enterprise customers, it is tough to get them to switch from one platform to another, so it could be a while before Meet sees a good amount of users using it.