I agree, if your concern is possession of the phone, then soft tokens are almost equal to SMS. The big difference is the ability to intercept the code out on the network (VoIP, Google Voice, etc...).
One thing that I have seen done with RSA tokens that could be done with software tokens as well as SMS tokens would be appending a PIN to the token. That way even if the token is stolen, the thief would need to know the PIN and where to append it. You don't need a biometric to unlock the token, just a password or PIN to be the 2nd factor.