I hate to inject gloom and doom into a fun topic like vanity bitcoin addresses... but y'all should be aware that one of my longer-term goals for the Bitcoin system is to make bitcoin addresses disappear.
This will make vanity addresses even better, they'll be like collector's items 
.But I'm guessing the techniques we are developing here may have some use even if Bitcoin addresses as we know them become obsolete.
ETA: Also, if I understand correctly, some form of address will still be used as an implementation detail, but just won't be externalized to end users. In this sense they will be like IP addresses - nobody knows which IP they're visiting, but they still exist. I suspect that if one could get a "vanity IP address" there would be a market for that, so no reason Bitcoin addresses would be different.
So, gloom and doom injection thwarted
.