By the time the rotors are kicking up dust from the landing area, isn't it a little late to be looking down at landing markers anyway?

It's very useful for games. Let's say you've made an online game, and you want settings for things like volume, key controls, etc. Sure, you could have the server remember those things and send them up to the flash player each time. But what if you have a different keyboard at home and want a different key layout? What if you want the volume off at work, but on at home? These are perfect applications for client-side flash variables.

Flash cookies are shared by all browsers.

That is incorrect, at the most permissive mode, a flash program can only access cookies from the same domain as where it was loaded from.

By which you mean "it's time for HTML5 in 3 years when IE9 penetration is high enough, assuming IE9 supports HTML5 when and if it comes out".