Well, I think WordPress Should care about this and come up with a FIX in version 2.7.
We, as webmasters, can’t control if our visitors or surfers download flash 10.. In fact, soon or late, most will download and install it.
Thus, every time they visit our site, they won’t be able to (for example) open an embeded flash video in full screen mode, since the new flash 10, blocks wordpress from opening flash videos in full screen. And this is just an example.
Not to name all the problems we have when we write a new post.
It is always easier, to FIX the server side problem (wordpress script). Than fix millions of flash installations in each of the computers around the world, that visit our site.
One FIX for one site.