For that to be a reality, we need to combine hardware wallets (https://en.bitcoin.it/wiki/Hardware_wallet http://www.bitcointrezor.com/), the new payment protocol (https://en.bitcoin.it/wiki/BIP_0070), and escrow transactions (https://en.bitcoin.it/wiki/Bitcoin_Escrow_Service), but the result would be pretty awesome.
I don't believe that bitcoin will destroy fiat or the finance industry as a whole, but I do think it will become a very convenient way of moving money around, especially between national currencies. Much in the same way that sending an email is more convenient than sending a letter internationally. It's not a complete solution; it's a foundation to build services upon, and those services will most likely be offered by the same large financial institutions we have today, along with a few upstarts. Just my 2 μBTC.