18 Months sounds OK, I guess. I don't really care. Every 12 months or so is kinda too frequent b/c then we'd have to pay $129 every time. Plus, the extra 6 or however many months would let Apple create more & better features, plus better stability.
I'm not totally sure if/what Apple's going to drop in 10.6. In 10.3, they needed USB ports (bye bye beige G3s!), in 10.4, they needed firewire ports (bye bye first iMacs!) and now, 10.5 needs an 867 MHz or faster G4 (bye bye all G3 iMacs, iBook G3s & Power Mac G3s and some G4s). I know in other threads there's been a debate on whether or not to drop PowerPC support, but good chance all G4s will be. On the one hand, G5s are more powerful than the first Intel Macs. However, if we keep G5s, but drop G4s, there aren't any G5 laptops in consumer's hands and laptops are a big chunk of the Mac population (or Apple pie
). It would suck for some people in either case. Either laptop users will be mad or G5 users will be mad. On yet a different hand, it might be easiest for Apple to drop all PowerPC support after 10.5 and focus only on Intel (and whatever the iPods/iPhone run). This would be a lot easier to maintain & program since there aren't so many different architectures. Plus, everyone who has a PowerPC Mac that wants to run 10.6 would have to buy a new Mac, meaning more sales for Apple. On the downside, the consumers will probably hate having to upgrade.