This is what I'd like BitcoinBank to do:
People deposit their bitcoins into accounts (login by username and maybe software token, if possible - even hardware).
Tax should be something 1% per year but i have no idea how to prevent people to add just 100 BTC when they open the account (tax 1BTC) and then add the next day another 10.000 BTC. One option could be to tax 1% per added bulk.
The wallet.dat holds all clients' bitcoins and the database hold sthe amount each is entitled to.
24-7 online banking for adding and withdrawing funds and payment intermediary.
Selling gold, silver, USD, EUR, GBP and other currencies on demand.
Selling virtual credit cards from multiple banks, in multiple currencies.
Wallet-lock options. Allows transfer of less than the amount set up by the user per day/week etc. Also one idea i have is a amount-protected lock, you can't move funds from your account to another bitcoin address unless you remember the passsum, ie: 255.78 BTC (might be useful for paranoids that need more layers of security)
Credits, based on trust. Dunno how to implement this yet.
Investment fund. Dunno if to implement this and how.
Also I dream of having the bank physically, with safe deposit boxes, maybe even microcip cards and all
At least two servers on different, secure, locations. Encryption in case of theft.
IDS and IPS with good sysadmins
Tor and I2P anonimity.
Gold, silver, bitcoin, USD, EUR and GBP reserve (might add chinese Yuan too)
at least these bitcoinbank domains: .eu, .com. org, .net, .biz to avoid scams
SSL certificate and GnuPGP keys