Vista's security chain works as designed and intended, preventing from you to inject an untrusted bootloader into the bootstrap. Isn't that what we -want- from our security systems? This isnt' a case of "Microsoft" holding our data hostage, this is a case of our own security policies WORKING.
If I were to be running Linux, with equivalent protection, I'd be right pissed if it could be trivially rootkitted/bypassed by swapping in a malicious bootloader.
The ONLY flaw I see in the entire Vista/TPM system is that users don't seem to have a way of manually trusting things they genuinely want to trust. If it hasn't been blessed by MS its not trusted -- that's a fine policy for general users, but if I, as the hardware want to trust a specific bit of code (e.g. the linux boot loader) then I should be able to manually sign it somehow, and add my personal key to my personal install of Vista. And then the grub bootloader I signed will be trusted on my (and only my) PC.
All the 'chatter on the internets' is currently centered around how to disable UAC, how to disable driver signing, how to go back to running windows as insecurely as possible. i would prefer to see the discussion take a more intelligent direction -- how to obtain keys/certificates, how to add them to Vista's chain of trust on a per PC or per domain basis, and how how sign code with them.
Signed drivers are a FANTASTIC idea. not being able to sign drivers myself for my own hardware is EVIL. But MS --does-- have programs in place to let you sign code with 'development drivers' which are designed to only be valid on your PC... its just that most of the discussion surround the issue is how to disable it, and how evil MS for deciding what is blessed and what is not.
I mean, take Stallman, even -he- who wrote the GPLv3 in part to counter DRM isn't against code signing. He just requires that the keys necessary to sign code be included, so the owner of the hardware and user of GPLv3 code can sign it, and thereby be free to make modifications and excercise all the freedoms intended by the gpl.