Macintouch, possibly the last news site without permanent links anywhere on the web, yesterday featured a couple of notes about Mac OS X 10.4. The first noted that the new OS version requires a FireWire port and a DVD drive. The first of these means that all but the "Pismo" PowerBook G3 are no longer supported, along with a list of G3 iMacs, but frankly these machines are probably a bit slow (and have maximum memory limits too low) for the OS anyway.
The second criteria is much more troublesome. As late as spring of 2003, Apple sold a low-end iBook with only a CD ROM drive. I know this because candace was buying her laptop on a budget, and that's exactly the model she has. I assume that the requirement for a DVD drive is more to do with the size of the installation than a real need for it in day to day use, but it does mean that I'm probably going to have to do some FireWire Target Disk Mode jiggerypokery, if that works at all, to get the OS installed. This is annoying.
The other comment, from Greg Chesney, says "For the first time since I've had a Mac (1987), I don't think I'll jump and order the newest version of the OS. Panther finally works pretty well, thank you very much Mr Jobs." I think he has a point; there aren't many killer features to upgrade to in 10.4. Unless, that is, you're a developer.
If you are, then you want Core Data, or Core Image, or Automator, or even Dashboard, to play with. And once you have them, you'll want to release apps that use them. Remember 18 months ago, when applications started requiring Mac OS X 10.3? It's because people were using bindings, or some other developer-focussed feature, that wasn't available in 10.2, and the same will happen this time.
In other words, you won't upgrade to 10.4 for the built-in applications; you'll upgrade for the stuff from third party developers that looks cool and wonderful, but which somehow doesn't support your current OS. I suspect that, as a strategy, it'll work out fine for Apple.