what is "TCB"?
Consider one thing though, "trusted computing" as a concept comes from the military. It is a computer the generals can put into the field and trust it to not leak classified info (be it the enemy, or the soldiers learning that their lives are being wasted).
So when you use such a computer, you have to ask yourself "trusted by whom?". Because it is also a lovely starting point for the *AA's to cram the file copying cat back in the bag.
Cryptography can be used to control you (for example, signed BIOS), or you can use it to be in control (encrypted email). I think that "trusted computing", when properly implemented, could be a powerful tool for users.
In this case, the concept of a "trusted computing base" is different from "Trusted Computing".
When you are in control of the trusted keys loaded in your machine, this allows you -the computer user- to defend against several classes of attacks, including many Evil Maid attacks.
Many Linux distros and most open source security software projects sign their releases for a really good reason.
"Trusted Computing" takes this a step further by pushing this signature verification into a tamper-resistant part of the computer, and verifying everything on the system, including (on some systems) the bootloader and the UEFI firmware.
It's only when the end-user doesn't have control of the trusted keys loaded into his computer that TC becomes something that can be used for great evil.