Quote - The fabricant has to agree to certain terms and conditions in order to receive a key; those terms including to keep the key a secret and to go to certain minimum lengths to prevent the key from ever being compromised, and to not use it to build a player that can compromise copy protection.

As I said before, the key is always the same for any fabricant and any fabricant that hasn't the key can easily get it by reverse engineering from other fabricant product, pay a bribe to some employee or by an exchange of favours between fabricants.

Quote - Under AACS, it is possible to revoke a key by removing it from the keyset from future disks.  Those discs would no longer work with that key (though there is nothing they could do about existing discs).

And you will need to buy a new player!!!!.  Imagine each time Hollywood releases a new movie you have to purchase an new DVD player!!!

All the ideas of Microsoft  about Vista will end as usual in a fracass, you must take into account:

1- Vista will require special hardware and will not be compatible with the existent hardware.
The question is, will the hardware fabricants have interest of making a special hardware for Vista?,  and which will be the price in the afirmative case?
The price of a hardware depend on the level of production, little production price very expensive, huge global production price very cheap.
To achieve a low price a product must be used all over the world by many applications, if Microsoft requires a special hardware to be used only with Vista, this is a limited market for a global production, so the cost will be much expensive.
You can add other requirement and is that Microsoft must aprove and give a certificate to the fabricant, not all the fabricants will be aproved or will have interest on making the hardware, so you can expect a few available fabricants or even only one.
As the number will be very small, the fabricants will raise their price due the higher production costs or the maximization of profits of Capitalism.

2- The second big problem is that Microsoft has problems with XP in Europa and Asia, Microsoft is not allowed to sell there XP as it is, it must sell a different version.
What pretends to do Microsoft with Vista is a clear violation of monopoly, privacy and customer rights laws, so Vista will be not allowed in EU and Asia unless many protection features are removed and documentation released.
The proposal of Vista will be sold only in the US, if Microsoft pretends to sell Vista outside the US it will need to sell a different version there.
The inmediate consequence is that you will have two kinds of harwares for Vista, a special hardware to be used by Vista-US and other hardware much similar or eqaul to the existen one to be used by Vista-not US. This fact will raise even more the price of an US computer able to run Vista.

The obvious result is the answering of this question:
"Do you will pay a very much higher price for a degraded performance computer by the only reason that is able to run Vista?"

Stupidity also evolves!