Dabears, a very good question!
It could be that with the release of WEM, wavoids all thought that preboot measurement was all done.
But WEM is Beta, and it sounds like while it was maybe complete for BIOS, it may not have been for UEFI. Now UEFI is very much more flexible and complex than BIOS, being easily programmable, meaning the opportunities for preboot malware skyrockets. So the introduction of UEFI will not only increase utility for enterprises but will also cause degrees of magnitude increases in malware risk. And with the increased risk the value proposition for deploying WEM, TPMs et al will increase dramatically as well.
