Before things get out of hand - the Surface RT does not have a TPM chip (so I was told) - a mechanism for providing hardware-level encryption and key generation.
Some Enterprises implement VPN policies that require a TPM. However, Android phones (and I believe iPhones) do NOT have TPM either, yet support VPN connectivity.
Actually, if you look in the Device Manager, you do see a TPM device, and as Bitlocker is used to encrypt the drive contents, this ties in with it having one.