Kurt Wagner at Re/code reports that Twitter is seriously considering a 10,000-characters-per-Tweet policy:
Twitter is currently testing a version of the product in which tweets appear the same way they do now, displaying just 140 characters, with some kind of call to action that there is more content you can’t see. Clicking on the tweets would then expand them to reveal more content. The point of this is to keep the same look and feel for your timeline, although this design is not necessarily final, sources say.
I’m fine with it. My timeline is full of screenshots of pages of text, long chains of tweetstorms, videos, animations, links to articles and Medium posts… if Twitter wants to make it easy to just embed full text inside of a Tweet, it should do it. The users are finding ways to attach lots of words to Tweets; Twitter should make it easier for them.