If anyone is interested in using a bip44 Wallet to generate
deterministic GPG identities, I have implemented a demonstration in
javascript.

http://memwallet.info/bip44ext/test.html

this allows a user to manage a GPG identity for encryption
and signing with zero bytes of permanent storage. (on tails for example)
One minor correction added which specifies that the smallest S value
should be used, to prevent different ecdsa implementations from creating
non-canonical/identical outputs.

comments welcome