I quickly went through this thread and counted the “votes” for a native div syntax.

- Daniel Staal: If I have to pick one, I'd pick blockquote.

- Shahbaz Youssefi: About divs: the block quote looks pretty nice.

- John Gabriele: I think side-marking is the right choice for divs 

- BP Jonsson: I definitely prefer surround marking

- Bernhard Weichel: My preferences would be 1. surround-marking 2. side-marking

- ousia: use surround-marking

- Nick Moffitt: I did feel that the blockquote syntax was a great visual cue

- me (mb21): I favour surround-marking

The result:

- blockquote/side-marking: 4

- surround-marking: 4

- (Plus two or three advocating for HTML-syntax for now)

Note that no-one is a fan of indented-blocks. Some arguments in favour of each idea:

Side-marking:

- more readable for long sections (because it’s always obvious that you’re in a div-environment, even if the section is longer than the height of your screen)

- more local (removing one line doesn’t change large parts of your document)

Surround-marking:

- more readable for short sections (because of the almost-line-long surrounding markers)

- doesn’t require a decent editor to write easily

- better for copy’n’pasting / wrapping existing stuff in a div