On the topic of vPro, I believe I've found something highly relevant: Intel's
response to the accusations.
http://communities.intel.com/community/vproexpert/blog/2010/02/04/intel-vpro-technology-privacy-and-security
In summary, if you don't want to visit the site:
Your computer can be accessed remotely only via a password generated by your
request
A red border will be displayed around the screen when remote access is
occurring, and there will also be a flashing icon
vPro does not operate when your computer is off
It can be disabled
Even if we don't know what the BIOS is doing, as you mentioned earlier, I
think the security is sufficient to dismiss all worries vPro. (But just in
case, I'll be closing my laptop every time I finish using it, which I'm sure
is good practice anyway.)