According to this CNet article, Research in Motion (RIM) will be releasing a Palm-like wireless handheld device today. The "I think this is a Palm killer" quote is credited to a source familiar with the device.
Details are sketchy and Mac connectivity is not addressed... I assume it's release will flesh out the details. Presumably it's a proprietary os.
Wireless handheld devices are the next step... Wouldn't email access everywhere be nice?
It has been rumored/speculated that Apple will release a Palm/Airport hybrid... but note that the Airport is only a wireless LAN solution.