Bonjour has been effectively deprecated. They haven't updated it in three years. The Airport Express has likewise been turned into abandonware. Apple was never good at networking and they've shown zero interest in working with companies that are. What I love is that they kept selling Time Capsules for about two years after they killed AFP in their operating system.

For a while, I was able to keep a SCSI-2 film scanner working over Firewire in an OS X environment. Then Steve Jobs died. And that, as they say, was that. Nowadays you're lucky to get 18 months of consistent functionality out of an iPhone. Your best move is to take a good hard look at the devices and software Apple is advertising their support of and discontinue literally everything else. Because if it's working now, it will suddenly stop one day when you most need it. I've been on the phone with tech support and had them say "yeah, well we've got email? But you really shouldn't use it. Unofficially our support tree for MobileMe is "use Gmail."