It isn't really possible to do anything useful yet on any scale,
I would say you can save some fees trading bitstampUSD/bitstampBTC on ripple instead of their main site.
as you cannot even set up an account as a business account - an account that forces destination-tags - which doing anything useful seems to pretty much require.
I haven't found where the client does this yet, but I'm currently looking for exactly this. This is the last clue I found (on the browser's console just before the issuer's official name loads in the trade page):
GET
https://ripple.bitstamp.net/ripple.txt So it seems part of the client and not the protocol. Currently they own the "centralized list of trusted gateways" but anyone could make his client look into another list or only support basic labels.
By the way, issuers could include more data than just their name, maybe even a legally binding digital signed contract or just a lot of details of the issued IOUs.
It seems to me that this is just the basic infrastructure code to enable more complex things.
Only speaking for myself, I but I would say that's why they've done it.
EDIT: now that someone mentioned namecoin for "storing color definitions", it comes to mind that this information is probably on the ledger, and consists exactly on that URL for bitstamp.
It seems to be this:
https://ripple.com/wiki/Transactions#AccountSet_.283.29"Domain VariableLength Optional
Domain associated with this account. Look up ripple.txt for the associated verification. The client will show the domain with a green background when it can be verified. Otherwise, as a strike out or red background. A length of 0 clears ledger entry."
https://ripple.com/wiki/RPC_API#unl_addCan't you use the client to make any rpc call you want to their servers?
I'm not exactly sure about what you mean by a "business account".