I'm also hoping some people/businesses will want to order their addresses in bulk, which could make things interesting...
Interesting idea. So, by ordering in bulk, you mean post multiple bounties with the same public key? Then the mining client can run them all at the same time, and when deciding which bounties to go after, it should sum the cost-reward of all bounties with the same public key.
Well, it could be either doing that, or posting a few bounties for the same vanity address prefix with different public keys. I guess the first method would be more preferable for people that provide solutions for a lot of different businesses, while the latter would be better for companies that want a number of addresses to identify with their one business. One or either way, it can be interesting...