There are tons and tons of hosts that still haven't upgraded to 5.3 - if the change comes in 5.5 or 6, it'll easily be 3+ years before it starts to be an issue.
Considering that a) no out-ass money has been offered me, and b) I'm effectively the only person who could even fix bugs in the system, they're still running 4.0.
Most of them are amazingly still in business, and their clients sites are still amazingly vulnerable. And we wonder why PHP has such a bad rep.