Indeed. Without out-of-the-box support in the major image editors like Photoshop and all the popular web browsers, I don't think we'll see JPEG overtaken any time soon.
Honestly, just last night I was looking and editing photos of a recent trip, and I uploaded them to tumblr to share on a small photo blog I just recently started. After spending some time trying to get the colors right, I realized that tumblr's image compression is god awfully horrendous. I felt so bad looking at my source JPEGs next to the tumblr post that I created a new flickr account right then.
I don't necessarily think JPEG is bad, or that it's even Tumblr's fault that I first thought to share photos there, but if any service/software started using BPG I think I would excitedly try it out.
If Chrome and Firefox implements this, then mod_pagespeed, for instance, can do the conversion on-the-fly also, services like CloudFlare can also do the conversion automatically.
