This would require something like lightning network or another scaling option, or a few major players dumping their billions into bitcoin (this would only happen if the USD showed signs of collapse). Otherwise bitcoin needs to scale to be able to transact at speeds similar to Visa . MC. Right now if mass adoption happened, bitcoin would collapse from the strain of network congestion and be so slow as to be unusable. This was proven by the August 1 fork that happened earlier this year. I have high hopes for bitcoin, but it will have to get over these technical hurdles first. This is how I think it will happen...

I expect the market cap to start spreading across several alt coins. I think bitcoin is the Yahoo! of finance. In relation to the internet, what happens next is the search engine wars (the proliferation of altcoins). Eventually one of these will likely become the next Google of finance. It could be a bitcoin modified by lightning network or something else.