Keep your eye on the FEDRAMP Cloud Initiative by the US Federal Gov.
One of the Controls is "Cryptographic Module Authentication, IA-7" and the device authenticating to the cloud server must use a FIPS 140 approved cryptographic Module. The Atmel and Novoton TPM and Infineon TPM in for approval will qualify. The NIAP TPM PP will define many other TPM forms.
"FIPS 140-2 Validated Cryptography for Secure Communications 29 The FedRAMP security control baseline includes IA-7, SC-8(1), SC-9(1), SC-13, and SC-13(1) all of which require 30 cryptographic mechanisms to prevent unauthorized disclosure of information during transmission unless 31 otherwise protected by alternative physical measures. If agency requirements stipulate FIPS 140-2 validated 32 cryptography be used from the agency to the cloud service provider, that should be specified."