i wouldnt say impossible, but almost impossible
![Roll Eyes](https://bitcointalk.org/Smileys/default/rolleyes.gif)
if banks start to use bitcoins, people would have more faith in bitcoin (i'm talking about people who doesnt know nothing about technology) and that would be good, these people would be always conected to a bank. But most of bitcoin users would still have their home wallet and/or their miner so they would never need a bank to use bitcoins.
people are skeptical with money, and unfortunately they trust banks.