Q: Does Steam Guard take advantage of the Intel® Identity Protection Technology solution that Valve and Intel recently announced?

A: No, not in this beta. We hope to offer additional forms of authentication soon though, so you'll have your choice of secondary authentication methods with Steam Guard.

So there goes the idea of "with your Steam account you can log on to any computer and play your games everywhere" ?

Why not? If Steam can access stuff, why can't your malware?

Consider it like this: You have in the Management Extensions (ME) on your motherboard a runspace for a generation routine. IPT generates a time dependant code (changes every 30 seconds) that can only be generated by the hardware. The actual key used for generation is not available. You can only generate the current ticket. One could steal these tickets, but after 30 seconds, it would become invalid. Malware could in theory generate such a code - though very unlikely as this is really complicated - but it would be also valid only 30 seconds. However, there is no way to access the keys used for generation from software, what brings the security. Without access to the hardware, there's no way to access the account.

If you know how Kerberos V works, the ticket idea is the same, only KRB5 uses 30 minutes as timeout interval.

No, no. I wasn't talking about stealing the key or a single generated code. I was talking about putting something on victim's machine that sends a fresh code to the attacker on an interval so the attacker always have a usable key.

With Steam Guard enabled, anyone attempting to login as you from an unrecognized computer must first provide additional, one-time authorization. A special access code will be sent to your contact email address, and this code must be entered into Steam before your first login on an unfamiliar computer is complete. You will also be notified if any login attempts from computers other than those you've authorized occur.

You will still be able to use your account on multiple PCs.

http://ipt.intel.com/how-it-works.aspx <- last but one question. IPT would be designed pretty badly if that wasn't possible.

In the unfortunate event that your PC is apprehended by a thief, they would also have to know your PC boot-up password, your Windows* password, ...

That would work, but it wouldn't be very reliable without any portforwarding, and would need a direct request of the attacker.