In reply to Tomas M..

Just to clarify that statement, post formats aren't going away. If they ever will, it'll be down the road, done as a separate task by a separate team, probably like the link menu.

Post formats are key to the genesis of blocks as a concept. Back in the 3.6 days, post formats as a 1st class citizen were being worked on for core, with a much bigger interface, the idea being that sometimes you want an "image post" to show in a different way than just a post with an image, and sometimes you wanted to show a "link post" where the link received a visual treatment akin to an opengraph card. This idea was sound enough, but the UI was pulled out because it was ultimately confusing.

They key take-away was that maybe you just want to write, and not have to worry about picking a format that's abstractly represented in the admin. More than that, maybe you want to write a standard post, but want the image to display the same way as if it was an image post. Maybe you want an "opengraph-style" link card inside that post.

Blocks can address that by basically making blocks for every post format. Want the image to look big and wide? There's a button for that. Want a big and bold quote in the middle of your post? Use the pullquote.

The idea being: the chief benefit that post formats brought — showing types of content in a different way — you can keep that, with a better preview, use those displays in standard posts, and not have to worry about picking a format.