The brand "OpenID" is prohibitively tech-y, and if presented with just those two options (OpenID or local) users will probably choose "local."
However, look at Gawker, HuffingtonPost and other seriously enormous site needing authenticated participation. All of them support Facebook, Twitter, etc. logins, and most users use those options instead of local login.
The OpenID/OAuth process (single central login, distributed authentication) is preferred by users, as long as you don't actually tell them that's what's happening.