I think bitcoin can not replace dollar soon.  Because still many people do not know about bitcoin.  And there are many millions people who still don't use Internet and than they how can depend on bitcoin.  So before the replacement of dollars, there is a urgent need that every person on earth can access the account and they should have a basic knowledge of Internet   than they can understand the bitcoins and till they will own the bitcoins.  Than there will be chances that bitcoin can replace dollars.  Bitcoin has strong potential but it needs and depends on Internet.  Without the access of Internet, bitcoin can be used,  stored  .