I’d like to address each idea individually:
Excellent idea! For technical posts, this absolutely makes sense, and I’d love to see some kind of option to embed a working example in a post. It would certainly make my Protip series more pleasant to look at…
This would be cool, but I think anyone who has the technical background required to embed data in some custom format can create an image of a chart and embed that image. A neat feature, but I don’t think it’s 100% necessary.
Awesome idea! We can use ImageMagick on the backend – I’ll add an item to my todo list, to explore ImageMagick filters for an hour or so one day. This could be a really fun feature, and cheap if we do it right.
Is there any way to do this with Markdown? I think our editor should support a Markdown mode in any case, but it may make this case in particular a lot easier. For now, people can cite sources like this 
 and have a reference at the bottom.
Personally, I’d like to have font options. Not too many – we don’t want the site to look like a circus. But a nice monospaced font would be excellent for technical posts that reference a lot of commands/code. That’s something that’s sorely missing in Medium’s editor, and something I’d like to correct in 2.0.
I’d also like to see changes highlighted in the editor when someone else changes the draft. That’s a major annoyance on Medium, and although it will be difficult to pull off correctly and consistently in 2.0, I think it’s something we’ll eventually need to have.