Some will call it undemocratic and thus bad, but I say it sometimes is the only way to restore sanity.
To quote one of my favourite lines of Nick Fury, "I recognize that the Council has made a decision, but given that it's a stupid ass decision, I have elected to ignore it."
 - http://youtube.com/watch?v=mOEr7kiysrE
In fact, for it to work at all, it'll have to be implemented in hardware or hardware-equivalent software (i.e. not in Firefox or anything where you can dump RAM or modify the software).
With file formats however, it's only software. Add supports to mainstream browers and operating systems and you've got a fully functional new format. Look how quickly webm came into existence.
JPEG is an oldy, but support for a new format that does all JPEG does is certainly possible, and it would slowly win out. Much like how png killed gif (until social media brought it roaring back... egh).