Ideas might take a while to get through, plus it's only a whitepaper proposal at the moment :)
edit: smart contract platforms like ethereum that doesn't deal only with social aspects might be bigger, but as far as attention economy goes, steem seems like it'll take the cake!
So do you think BAT may have a future with steem taking the lion's share?
They might work together, I'm not sure. But getting people to use a specific browser is quite a hard sell imo..