this!!
I know this is a bit off in a tangent, but after spending a week with the Range API and contenteditable, the frustration is truly immense .. it is truly astounding that file upload and rich text editing, yes, two of the most basic things, are not really solved problems on the web.
It's amazing.
But also kind've exciting :)
I've spent months on this problem. The challenge is that the behavior you want (text ranges) does not map well onto the DOM (trees). This takes some thought but isn't THAT bad. Browser bugs also play a role since the code paths aren't used that often but the main reason is the w3c Range API is the worst API I am aware of in any language and everything you could use to replace it is not cross browser.