Well, thanks for all the feedback.
Guess I'll be implementing regular login and maybe implement OpenID on the side as an afterthought.
I think a lot of the concerns expressed here comes down to singling out an OpenID provider (there are many) that you trust.
Personally, I'd be inclined to use such a solution (openID) for anything that is not of vital importance (a gaming website, even one that charges for it's usage, would fall into that non-vital category).
However, I recognize that some of the concerns presented here will mirror some of the concerns potential users will have and it is to them that I am catering to.
Side note: My main concern at this point with most form of online authentication is that lack of association between it and RL identity (nothing approaching the reliability of your driver's license here). Hopefully, this will be addressed as some point in the future, if governments start cooperating to find a lasting solution to that problem.
AndrewC: Honestly, I think you're better off ignoring OpenID and going with a specific implementation such as Facebook Connect, as more people have a Facebook account than an OpenID provider (or better said, few people know they generally have an OpenID provider).
I disagree with you there.
Personally, I have a yahoo and gmail account, but no Facebook.
At least, OpenID gives the user some options there and I'll want to make sure that my users have those options.
I would never take a path that would tie me down so tightly with a singular commercial provider.
This is consistent with some of the decisions I've made so far (for example, moving away from Windows and going with Linux).