I see parallels in how mp3 encoding became a dominant force on the music industry.

mp3 created ==> Digital Distribution ==> Napster moment ==> Media Companies dying/displaced ==> Artists making income directly with no interference

bitcoin created ==> Digital wealth distribution ==> < insert catalyst > ==> Banks and Financial systems dying/displaced ==> Individuals trading freely for services and goods with no interference

The question really is - what is the catalyst going to be, overall adoption 'tipping point' or some other event. And when/how fast this will occur.

I believe bitcoin will displace currencies managed by fallible humans. One other possibility however, is that sovereigns will start their own blockchains so they can apply taxation controls - making it illegal to not participate in their system. A bit horrifying, but that is a possibility if they embrace the technology and refuse to partake in the 'open' version.

I guess we'll see....