The problem with your posting is that you never got around to listing a single recent item that was being obsoleted (No, the Lisa doesn't count).
I understand your frustration at not being able to buy all the latest Apple toys, but the old stuff still works. It even works with the latest OS. I'm using a last generation Titanium Powerbook G4 and it runs Leopard just fine. It's not as fast or shiny as the MacBook Air, but I can still be productive on it and am in no hurry or need of a new notebook.