It's possible to create transactions that require signatures from several different people to spend. With some extra coding work, you could set up Bitcoin to keep (say) 500 BTC liquid and spendable by anyone, the rest would be automatically locked such that signatures from 3 different people were required to spend it.
That feature isn't available today, but it might help in future.
Just thinking out loud, and I am no programmer, nor do I own such a biz, but it would be nice if a hypothetical BTC Enterprise client allowed you to store your BTC's P2P under conditions set when you store them. So if I had a business with some incoming BTC, I could set that I want to store them (or at least catalogue the freezing on spending the designated BTCs) in the P2P cloud (which perhaps is perhaps comprised of all the other Enterprise clients) and only be allowed access (or the ability to spend the designated BTCs) should certain conditions be met (perhaps 3+ of some set of designated clients, confirming). Obviously there could be other conditions set. This would lessen the need for BTC banks. I wonder if you could also in this way make time based deposits, so one condition being your deposit could be lent out to the market, for a fee, and you could not withdraw/spend until a certain date. Anyway my $0.02, er 0.02BTC.