As someone who is still holding onto his Zire (five years now?) and is about to upgrade to Snow Leopard: this isn't going to impact me because it only changes syncing the Apple calendars and contacts. Sure it would be nice if Apple supported the conduit but I figure it simply: Microsoft never supported ActiveSync for PalmOS, why are people getting concerned when Apple is dropping support for PalmOS since they were the ones writing it themselves not the product vendor? Given Palm's recent bout of laziness in abusing iTunes to support their device, I can't fault Apple for not wanting to support Palm's unsupported proprietary device.
It would be nice if it was all integrated but I'm still going to be able to sync my device using the ancient Palm Desktop tool. There is the Missing Sync which provides support for the Palm under Mac. All that is happening is that Apple isn't shipping some code they wrote probably because it was going to be a pain to port it to 64-bit.
To be quite honest, so far they've gone above and beyond.