With TrueCrypt not officially supporting Windows 8 yet, Bitlocker appears to be the default option for full disk encryption on a new laptop. However, Bitlocker suffers a major usability degradation on systems without a TPM (need to store keys on a flashdrive or enter a 48 digit pin instead of a password).
My problem is that I can't find any way to determine if a laptop is equipped with a TPM; even looking at models that I know have them (eg Dell Latitude) it doesn't appear to be listed anywhere.