currently allot of people/new investors are now using btc's as some kind of trading and long term investment with expected growth but not as actual cash.
the scope will only be limited to those that have access to the client, developing countries will have to use an eftpos type client to start with
unless one of the big tech companies decides to release a dedicated mobile handset that holds the blockchain and can be cheap enough for
mass adoption, i can see massive potential here for someone to actually just pick the best priced android handset, mod re-brand and re-release it,
after initial sales are in then funds could be allocated for software upgrades to fix bugs or security patches that need to be implemented