Is there a hardware wallet project that plans to add multisig capabilities?
This isn't exactly what you want, but it's close:

The Case hardware wallet uses 2-of-3 multisig, where one key is on the device, one is on Case servers, and the third recovery key has two options: Self-storage or Vault storage through Third Key Solutions (invisible to the customer). If you choose the self-storage option, you provide an xpub key during initial setup, and the multisig wallet will use that as the third key. 

In that scheme you would have signing control of 2 of the 3 keys. There is still the human trust element where Case servers are necessary to perform the transactions, but they cannot sign any transactions not initiated by the user. 

Full disclosure: I work at Case.