I think increasing character limit from 140 to 10,000 on twitter is not a good idea. The real fun of tweeting 140 characters instantly about your day or work was easy and not that time consuming. In short it will change the idea of using Twitter as a microblogging site to say something in a simple and short way to anyone, that everyone in the world can see.
Also the current version of the expanded tweets shows them as the normal 140, but gives people the option to click the full thing, according to reports. This will help many artists which use twitter as a platform to promote or build their brand in today’s world social media.