Released today is an OpenSSL 0.9.8 TPM engine. This engine is compiled as a shared object and can be loaded using an included openssl.cnf file for apps that have openssl config support.
Right now, RAND and RSA are supported by the engine. RSA key generation is done inside the TPM. Also included is create_tpm_key, a utility to create a TPM key and write it to disk, which can then be loaded through the engine using OpenSSL's ENGINE_load_private_key function.
Please send comments to email@example.com, I'd be interested to know how people would like to use this engine and what features you're all looking for.